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Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Imaging and sensing based on muon tomography  

DOE Patents [OSTI]

Techniques, apparatus and systems for detecting particles such as muons for imaging applications. Subtraction techniques are described to enhance the processing of the muon tomography data.

Morris, Christopher L; Saunders, Alexander; Sossong, Michael James; Schultz, Larry Joe; Green, J. Andrew; Borozdin, Konstantin N; Hengartner, Nicolas W; Smith, Richard A; Colthart, James M; Klugh, David C; Scoggins, Gary E; Vineyard, David C

2012-10-16T23:59:59.000Z

2

Discussion - Next Step for Fukushima Daiichi Muon Tomography  

SciTech Connect (OSTI)

Specification of Fukushima Daiichi Muon Tomography (FMT): (1) 18-feet (5.5-m) drift tube, 2-inch (5-cm) diameter; (2) 108 tubes per layer; (3) Unit layer = 2 layer (detection efficiency: 0.96 x 0.96 = 92%); (4) 12 or 16 layer per module; (5) 16 layers allows momentum analysis at 30% level; (6) 2 module per super module (5.5 x 11 m{sup 2}); and (7) FMT = 2 super module. By deploying MMT next to a research reactor, we will be able to measure the impact of low level radiation fields on muon tomography and reconstruction processes. Radiation level during reactor operation is {approx}50 {micro}Sv/h which provides similar radiation environment of inside the FMT radiation shield at Fukushima Daiichi. We will implement coincidence algorithm on the FPGA board.

Miyadera, Haruo [Los Alamos National Laboratory

2012-08-13T23:59:59.000Z

3

Our Next Two Steps for Fukushima Daiichi Muon Tomography  

SciTech Connect (OSTI)

After the vast disasters caused by the great earthquake and tsunami in eastern Japan, we proposed applying our Muon Tomography (MT) technique to help and improve the emergency situation at Fukushima Daiichi using cosmic-ray muons. A reactor-tomography team was formed at LANL which was supported by the Laboratory as a response to a request by the former Japanese Prime Minister, Naoto Kan. Our goal is to help the Japanese people and support remediation of the reactors. At LANL, we have carried out a proof-of-principle technical demonstration and simulation studies that established the feasibility of MT to image a reactor core. This proposal covers the next two critical steps for Fukushima Daiichi Muon Imaging: (1) undertake case study mock-up experiments of Fukushima Daiichi, and (2) system optimization. We requested funding to the US and Japanese government to assess damage of reactors at Fukushima Daiichi. The two steps will bring our project to the 'ready-to-go' level.

Miyadera, Haruo [Los Alamos National Laboratory

2012-04-11T23:59:59.000Z

4

Nuclear Waste Imaging and Spent Fuel Verification by Muon Tomography  

E-Print Network [OSTI]

This paper explores the use of cosmic ray muons to image the contents of shielded containers and detect high-Z special nuclear materials inside them. Cosmic ray muons are a naturally occurring form of radiation, are highly penetrating and exhibit large scattering angles on high Z materials. Specifically, we investigated how radiographic and tomographic techniques can be effective for non-invasive nuclear waste characterization and for nuclear material accountancy of spent fuel inside dry storage containers. We show that the tracking of individual muons, as they enter and exit a structure, can potentially improve the accuracy and availability of data on nuclear waste and the contents of Dry Storage Containers (DSC) used for spent fuel storage at CANDU plants. This could be achieved in near real time, with the potential for unattended and remotely monitored operations. We show that the expected sensitivity, in the case of the DSC, exceeds the IAEA detection target for nuclear material accountancy.

Jonkmans, G; Jewett, C; Thompson, M

2012-01-01T23:59:59.000Z

5

Characterising encapsulated nuclear waste using cosmic-ray muon tomography  

E-Print Network [OSTI]

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the UK Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

Anthony Clarkson; David J. Hamilton; Matthias Hoek; David G. Ireland; John R. Johnstone; Ralf Kaiser; Tibor Keri; Scott Lumsden; David F. Mahon; Bryan McKinnon; Morgan Murray; Siân Nutbeam-Tuffs; Craig Shearer; Guangliang Yang; Colin Zimmerman

2014-10-27T23:59:59.000Z

6

Characterising encapsulated nuclear waste using cosmic-ray muon tomography  

E-Print Network [OSTI]

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the UK Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, John R; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Siân; Shearer, Craig; Yang, Guangliang; Zimmerman, Colin

2014-01-01T23:59:59.000Z

7

Neutron Tomography and Space  

E-Print Network [OSTI]

Kevin Shields, “Optimization of neutron tomography for rapidNEUTRON TOMOGRAPHY AND SPACE Hal Egbert, Ronald Walker, R.industrial applications[1]. Neutron Computed Tomography was

Egbert, Hal; Walker, Ronald; Flocchini, R.

2007-01-01T23:59:59.000Z

8

Pseudolocal tomography  

DOE Patents [OSTI]

Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density. 7 figs.

Katsevich, A.J.; Ramm, A.G.

1996-07-23T23:59:59.000Z

9

Pseudolocal tomography  

DOE Patents [OSTI]

Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density.

Katsevich, Alexander J. (Los Alamos, NM); Ramm, Alexander G. (Manhattan, KS)

1996-01-01T23:59:59.000Z

10

Doppler Tomography  

E-Print Network [OSTI]

I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

T. R. Marsh

2000-11-01T23:59:59.000Z

11

The Design and Performance of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers  

E-Print Network [OSTI]

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons are increasingly being exploited for the non-destructive assay of shielded containers in a wide range of applications. One such application is the characterisation of legacy nuclear waste materials stored within industrial containers. The design, assembly and performance of a prototype muon tomography system developed for this purpose are detailed in this work. This muon tracker comprises four detection modules, each containing orthogonal layers of Saint-Gobain BCF-10 2mm-pitch plastic scintillating fibres. Identification of the two struck fibres per module allows the reconstruction of the incoming and Coulomb-scattered muon trajectories. These allow the container content, with respect to the atomic number Z of the scattering material, to be determined through reconstruction of the scattering location and magnitude. On each detection layer, the light emitted by the fibre is detected by a single Hamamatsu H8500 MAPMT with two fibre...

Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, Russell; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Sian; Shearer, Craig; Staines, Cassie; Yang, Guangliang; Zimmerman, Colin

2013-01-01T23:59:59.000Z

12

GEANT4 Simulation of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers  

E-Print Network [OSTI]

Cosmic-ray muons are highly penetrative charged particles that are observed at sea level with a flux of approximately one per square centimetre per minute. They interact with matter primarily through Coulomb scattering, which is exploited in the field of muon tomography to image shielded objects in a wide range of applications. In this paper, simulation studies are presented that assess the feasibility of a scintillating-fibre tracker system for use in the identification and characterisation of nuclear materials stored within industrial legacy waste containers. A system consisting of a pair of tracking modules above and a pair below the volume to be assayed is simulated within the GEANT4 framework using a range of potential fibre pitches and module separations. Each module comprises two orthogonal planes of fibres that allow the reconstruction of the initial and Coulomb-scattered muon trajectories. A likelihood-based image reconstruction algorithm has been developed that allows the container content to be det...

Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, Russell; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Sian; Shearer, Craig; Staines, Cassie; Yang, Guangliang; Zimmerman, Colin

2013-01-01T23:59:59.000Z

13

Analysis of the multigroup model for muon tomography based threat detection  

SciTech Connect (OSTI)

We compare different algorithms for detecting a 5?cm tungsten cube using cosmic ray muon technology. In each case, a simple tomographic technique was used for position reconstruction, but the scattering angles were used differently to obtain a density signal. Receiver operating characteristic curves were used to compare images made using average angle squared, median angle squared, average of the squared angle, and a multi-energy group fit of the angular distributions for scenes with and without a 5?cm tungsten cube. The receiver operating characteristic curves show that the multi-energy group treatment of the scattering angle distributions is the superior method for image reconstruction.

Perry, J. O.; Bacon, J. D.; Borozdin, K. N.; Fabritius, J. M.; Morris, C. L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-02-14T23:59:59.000Z

14

Modulated Luminescent Tomography  

E-Print Network [OSTI]

modalities behave differently than Photoacoustic and Thermoacoustic Tomography, where the ex- citation is highly diffusive but the emitted ultrasound signal ...

2015-01-28T23:59:59.000Z

15

Turbocharging Quantum Tomography.  

SciTech Connect (OSTI)

Quantum tomography is used to characterize quantum operations implemented in quantum information processing (QIP) hardware. Traditionally, state tomography has been used to characterize the quantum state prepared in an initialization procedure, while quantum process tomography is used to characterize dynamical operations on a QIP system. As such, tomography is critical to the development of QIP hardware (since it is necessary both for debugging and validating as-built devices, and its results are used to influence the next generation of devices). But tomography su %7C ers from several critical drawbacks. In this report, we present new research that resolves several of these flaws. We describe a new form of tomography called gate set tomography (GST), which unifies state and process tomography, avoids prior methods critical reliance on precalibrated operations that are not generally available, and can achieve unprecedented accuracies. We report on theory and experimental development of adaptive tomography protocols that achieve far higher fidelity in state reconstruction than non-adaptive methods. Finally, we present a new theoretical and experimental analysis of process tomography on multispin systems, and demonstrate how to more e %7C ectively detect and characterize quantum noise using carefully tailored ensembles of input states.

Blume-Kohout, Robin J; Gamble, John King,; Nielsen, Erik; Maunz, Peter Lukas Wilhelm; Scholten, Travis L.; Rudinger, Kenneth Michael

2015-01-01T23:59:59.000Z

16

GEANT4 Simulation of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers  

E-Print Network [OSTI]

Cosmic-ray muons are highly penetrative charged particles that are observed at sea level with a flux of approximately one per square centimetre per minute. They interact with matter primarily through Coulomb scattering, which is exploited in the field of muon tomography to image shielded objects in a wide range of applications. In this paper, simulation studies are presented that assess the feasibility of a scintillating-fibre tracker system for use in the identification and characterisation of nuclear materials stored within industrial legacy waste containers. A system consisting of a pair of tracking modules above and a pair below the volume to be assayed is simulated within the GEANT4 framework using a range of potential fibre pitches and module separations. Each module comprises two orthogonal planes of fibres that allow the reconstruction of the initial and Coulomb-scattered muon trajectories. A likelihood-based image reconstruction algorithm has been developed that allows the container content to be determined with respect to the atomic number Z of the scattering material. Images reconstructed from this simulation are presented for a range of anticipated scenarios that highlight the expected image resolution and the potential of this system for the identification of high-Z materials within a shielded, concrete-filled container. First results from a constructed prototype system are presented in comparison with those from a detailed simulation. Excellent agreement between experimental data and simulation is observed showing clear discrimination between the different materials assayed throughout.

Anthony Clarkson; David J. Hamilton; Matthias Hoek; David G. Ireland; Russell Johnstone; Ralf Kaiser; Tibor Keri; Scott Lumsden; David F. Mahon; Bryan McKinnon; Morgan Murray; Sian Nutbeam-Tuffs; Craig Shearer; Cassie Staines; Guangliang Yang; Colin Zimmerman

2013-09-13T23:59:59.000Z

17

Dual seven pinhole tomography  

SciTech Connect (OSTI)

Emission tomography using two orthogonal sets of projections through seven pinhole collimators is considered. This paper describes the acquisition system, the reconstruction algorithm, presents results obtained in phantom studies, and discusses the advantages and disadvantages of this method over conventional Seven Pinhole Tomography.

Bizais, Y.; Zubal, I.G.; Rowe, R.W.; Bennett, G.W.; Brill, A.B.

1982-01-01T23:59:59.000Z

18

Geometric Tomography: A Limited-View Approach for Computed Tomography  

E-Print Network [OSTI]

Geometric Tomography: A Limited-View Approach for Computed Tomography Peter B. Noël, Jinhui Xu Keywords Computed Tomography; Geometric Compressed Sensing; Topo- logical Peeling. ABSTRACT Computed to generate 3D data, denoted f, directly from projec- tions, denoted g. Thus, the projection relationship can

Corso, Jason J.

19

Neutron computed tomography  

E-Print Network [OSTI]

to make the Donner Algorithms run. TABLE OF CONTEliiTS CHAPTF. . R I NEI. TRON RADIOGRAPHY . I. 1 Background . I. 2 Theory . l. 3 Neutron Beam Characterization I. 4 Image Detectors . COMPI'TED TOMOGRAPHY . Il I Background . II. 2 Notation II. 3... data which is generated by rays traveling (and being attenuated) in straight lines. However in neutron radiography, what is measured is, to most extents, the levels of neutrons which are not attenuated. Neutrons are particles. They scatter...

Russell, Clifford Marlow

2012-06-07T23:59:59.000Z

20

Enhanced local tomography  

DOE Patents [OSTI]

Local tomography is enhanced to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. In a first method for evaluating the value of the discontinuity, the relative attenuation data is inputted to a local tomography function .function..sub..LAMBDA. to define the location S of the density discontinuity. The asymptotic behavior of .function..sub..LAMBDA. is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA.. In a second method for evaluating the value of the discontinuity, a gradient value for a mollified local tomography function .gradient..function..sub..LAMBDA..epsilon. (x.sub.ij) is determined along the discontinuity; and the value of the jump of the density across the discontinuity curve (or surface) S is estimated from the gradient values.

Katsevich, Alexander J. (Los Alamos, NM); Ramm, Alexander G. (Manhattan, KS)

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Generalized local emission tomography  

DOE Patents [OSTI]

Emission tomography enables locations and values of internal isotope density distributions to be determined from radiation emitted from the whole object. In the method for locating the values of discontinuities, the intensities of radiation emitted from either the whole object or a region of the object containing the discontinuities are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the isotope density discontinuity. The asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) knowing pointwise values of the attenuation coefficient within the object. In the method for determining the location of the discontinuity, the intensities of radiation emitted from an object are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the density discontinuity and the location .GAMMA. of the attenuation coefficient discontinuity. Pointwise values of the attenuation coefficient within the object need not be known in this case.

Katsevich, Alexander J. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

22

Optical Tomography in two dimensions  

E-Print Network [OSTI]

so-called diffused tomography [SGKZ]. Other areas of applications are atmospheric remote sensing [Bi], nuclear physics (see [MC] for a review), etc. We describe ...

23

Radial reflection diffraction tomography  

DOE Patents [OSTI]

A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

Lehman, Sean K.

2012-12-18T23:59:59.000Z

24

Positron Emission Tomography (PET)  

DOE R&D Accomplishments [OSTI]

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

Welch, M. J.

1990-01-00T23:59:59.000Z

25

Atom Probe Tomography | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone byDear Friend,Arthur J. NozikAtom Probe Tomography Atom Probe

26

Thermoacoustic tomography with variable sound speed  

E-Print Network [OSTI]

We study the mathematical model of thermoacoustic tomography in media with a ... In thermoacoustic tomography, a short electro-magnetic pulse is sent through ...

2009-10-26T23:59:59.000Z

27

Electrical Impedance Tomography Liliana Borcea  

E-Print Network [OSTI]

Electrical Impedance Tomography Liliana Borcea #3; September 3, 2002 Abstract We review theoretical and numerical studies of the inverse problem of electrical impedance tomography which seeks the electrical conductivity and permittivity inside a body, given simul- taneous measurements of electrical currents

Borcea, Liliana

28

Teleseismic transmission and reflection tomography  

E-Print Network [OSTI]

The aim of seismic tomography is to determine a model of Earth properties that best explain observed seismic data. In practice, the limitations placed on our observations and computational capabilities force us to make a ...

Burdick, Scott A. (Scott Anthony)

2014-01-01T23:59:59.000Z

29

TE Connectivity Finds Answers in Tomography  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the...

30

Thermoacoustic and Photoacoustic Tomography ... - Purdue University  

E-Print Network [OSTI]

Thermoacoustic and Photoacoustic Tomography with a variable continuous or discontinuous sound speed. Plamen Stefanov. Purdue University. Based on a ...

Plamen Stefanov

2010-11-09T23:59:59.000Z

31

Electron tomography of dislocation structures  

SciTech Connect (OSTI)

Recent developments in the application of electron tomography for characterizing microstructures in crystalline solids are described. The underlying principles for electron tomography are presented in the context of typical challenges in adapting the technique to crystalline systems and in using diffraction contrast imaging conditions. Methods for overcoming the limitations associated with the angular range, the number of acquired images, and uniformity of image contrast are introduced. In addition, a method for incorporating the real space coordinate system into the tomogram is presented. As the approach emphasizes development of experimental solutions to the challenges, the solutions developed and implemented are presented in the form of examples.

Liu, G.S.; House, S.D.; Kacher, J. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Tanaka, M.; Higashida, K. [Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Robertson, I.M., E-mail: irobertson@wisc.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

2014-01-15T23:59:59.000Z

32

Discrete Tomography: A Neural Network Approach  

E-Print Network [OSTI]

Abstract Tomography tries to reconstruct an object from a number of projections in multiple directions quality reconstructions from a limited set of projections, while avoiding image artifacts that are often present in traditional approaches. 1 Introduction Tomography, or more especially computed tomography

Kosters, Walter

33

Computed tomography:the details.  

SciTech Connect (OSTI)

Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

Doerry, Armin Walter

2007-07-01T23:59:59.000Z

34

Measuring momentum for charged particle tomography  

DOE Patents [OSTI]

Methods, apparatus and systems for detecting charged particles and obtaining tomography of a volume by measuring charged particles including measuring the momentum of a charged particle passing through a charged particle detector. Sets of position sensitive detectors measure scattering of the charged particle. The position sensitive detectors having sufficient mass to cause the charged particle passing through the position sensitive detectors to scatter in the position sensitive detectors. A controller can be adapted and arranged to receive scattering measurements of the charged particle from the charged particle detector, determine at least one trajectory of the charged particle from the measured scattering; and determine at least one momentum measurement of the charged particle from the at least one trajectory. The charged particle can be a cosmic ray-produced charged particle, such as a cosmic ray-produced muon. The position sensitive detectors can be drift cells, such as gas-filled drift tubes.

Morris, Christopher (Los Alamos, NM); Fraser, Andrew Mcleod (Los Alamos, NM); Schultz, Larry Joe (Los Alamos, NM); Borozdin, Konstantin N. (Los Alamos, NM); Klimenko, Alexei Vasilievich (Maynard, MA); Sossong, Michael James (Los Alamos, NM); Blanpied, Gary (Lexington, SC)

2010-11-23T23:59:59.000Z

35

Earthquake Forecast via Neutrino Tomography  

E-Print Network [OSTI]

We discuss the possibility of forecasting earthquakes by means of (anti)neutrino tomography. Antineutrinos emitted from reactors are used as a probe. As the antineutrinos traverse through a region prone to earthquakes, observable variations in the matter effect on the antineutrino oscillation would provide a tomography of the vicinity of the region. In this preliminary work, we adopt a simplified model for the geometrical profile and matter density in a fault zone. We calculate the survival probability of electron antineutrinos for cases without and with an anomalous accumulation of electrons which can be considered as a clear signal of the coming earthquake, at the geological region with a fault zone, and find that the variation may reach as much as 3% for $\\bar \

Bin Wang; Ya-Zheng Chen; Xue-Qian Li

2011-03-29T23:59:59.000Z

36

Self-guided quantum tomography  

E-Print Network [OSTI]

We introduce a self-learning tomographic technique in which the experiment guides itself to an estimate of its own state. Self-guided quantum tomography (SGQT) uses measurements to directly test hypotheses in an iterative algorithm which converges to the true state. We demonstrate through simulation on many qubits that SGQT is a more efficient and robust alternative to the usual paradigm of taking a large amount of informationally complete data and solving the inverse problem of post-processed state estimation.

Christopher Ferrie

2014-11-10T23:59:59.000Z

37

THERMOACOUSTIC TOMOGRAPHY ARISING IN BRAIN IMAGING ...  

E-Print Network [OSTI]

In this paper, we study the mathematical model of thermoacoustic and photoacoustic tomography for a sound speed that jumps across a smooth closed surface.

2011-02-21T23:59:59.000Z

38

Computed Tomography software and standards  

SciTech Connect (OSTI)

This document establishes the software design, nomenclature, and conventions for industrial Computed Tomography (CT) used in the Nondestructive Evaluation Section at Lawrence Livermore National Laboratory. It is mainly a users guide to the technical use of the CT computer codes, but also presents a proposed standard for describing CT experiments and reconstructions. Each part of this document specifies different aspects of the CT software organization. A set of tables at the end describes the CT parameters of interest in our project. 4 refs., 6 figs., 1 tab.

Azevedo, S.G.; Martz, H.E.; Skeate, M.F.; Schneberk, D.J.; Roberson, G.P.

1990-02-20T23:59:59.000Z

39

Understanding Atom Probe Tomography of Oxide-Supported Metal...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Understanding Atom Probe Tomography of Oxide-Supported Metal...

40

Using X-Ray Computed Tomography in Pore Structure Characterization...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Using X-Ray Computed Tomography in Pore Structure Characterization for a Berea Sandstone: Resolution Effect. Using X-Ray Computed Tomography in Pore Structure Characterization for...

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Surface Impedance Tomography for Antarctic Sea Ice  

E-Print Network [OSTI]

Surface Impedance Tomography for Antarctic Sea Ice C. Sampsona , K. M. Goldena , A. Gullya , A. P, Australia Abstract During the 2007 SIPEX expedition in pack ice off the coast of East Antarctica, we measured the electrical conductivity of sea ice via surface impedance tomography. Resistance data from

Golden, Kenneth M.

42

ALGEBRAIC ASPECTS OF EMISSION TOMOGRAPHY WITH ABSORPTION  

E-Print Network [OSTI]

ALGEBRAIC ASPECTS OF EMISSION TOMOGRAPHY WITH ABSORPTION L. Hajdu and R. Tijdeman Abstract of emission tomography with absorption, con- sider a ray (such as light or X-ray) transmitting through #1; e #22;x ; where #22; #21; 0 denotes the absorption coeÃ?cient of the material, and x is the length

Tijdeman, Robert

43

Fast Globally Convergent Reconstruction in Emission Tomography  

E-Print Network [OSTI]

considerable speedup by using only a subset of the projection data per sub- iteration. However, OSEM1 Fast Globally Convergent Reconstruction in Emission Tomography Using COSEM, an Incremental EM globally convergent incremental EM algorithms for reconstruction in emission tomography, COSEM- ML

Rangarajan, Anand

44

Positron emission tomography wrist detector  

DOE Patents [OSTI]

A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

Schlyer, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY)

2006-08-15T23:59:59.000Z

45

Collimator-free photon tomography  

DOE Patents [OSTI]

A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image. 6 figs.

Dilmanian, F.A.; Barbour, R.L.

1998-10-06T23:59:59.000Z

46

Collimator-free photon tomography  

DOE Patents [OSTI]

A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image.

Dilmanian, F. Avraham (Yaphank, NY); Barbour, Randall L. (Westbury, NY)

1998-10-06T23:59:59.000Z

47

Positron Emission Tomography Physics, Instrumentation, Data Analysis  

E-Print Network [OSTI]

1 Positron Emission Tomography Physics, Instrumentation, Data Analysis Carl K. Hoh, MD Department fast computer Filtered Back Projection Iterative Reconstruction PET Image Reconstruction #12 PET Scanner Design · Smaller individual crystal size = better spatial resolution · Physical limit

Liu, Thomas T.

48

Economical standard quantum process tomography  

E-Print Network [OSTI]

Recently, Bendersky \\emph{et al.} developed a method to complete the task of characterizing an arbitrary $\\chi$ matrix element in a scalable way, Phys. Rev. Lett. Vol. \\textbf{100}, 190403(2008), where an auxiliary system was needed. In present work, we shall show that the same task can also be completed within the scheme of standard quantum process tomography (SQPT) where there is no requirement for ancilla. Our method depends on two observations: With the elaborately chosen operators basis, the SQPT may have an economical form where a single run of experiment, in which we measure the expectation value of a chosen operator in the outport of the quantum channel with a known input, is sufficient to characterize a selected $\\chi$ matrix element; With the progress recently achieved in quantum entanglement detection, we also find that the number of the experimental settings to realize the experiment for the selected $\\chi$ matrix element does not exceed 2N for the N-qubits system. For practice, our scheme can be applied for the cases where the controlled two-body interaction is neither available nor desirable.

Xiaohua Wu; Ke Xu

2010-11-30T23:59:59.000Z

49

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network [OSTI]

, "A fast forward solver of radiative transfer equation," Transport Theory and Statistical Physics 38Multilevel bioluminescence tomography based on radiative transfer equation Part 1: l1 approach for bioluminescence tomography based on radiative transfer equation with the emphasis on improving

Soatto, Stefano

50

Tomography and High-Resolution Electron Microscopy Study of Surfaces...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Tomography and High-Resolution Electron Microscopy Study of Surfaces and Porosity in a Plate-Like ?-Al2O3. Tomography and High-Resolution Electron Microscopy Study of...

51

Evaluation of Turbine Blades Using Computed Tomography  

E-Print Network [OSTI]

Turbine blades are high value castings having complex internal geometry. Computed Tomography has been employed on Turbine blades for finding out defects and internal details. The wall thickness, rib thickness and radius of curvature are measured from the CT slices. The discontinuities including blockages of cooling passages in the cast material can be detected. 3D visualization of the turbine blade provides in extracting its internal features including inaccessible areas nondestructively, which is not possible through conventional NDE methods. The salient features for evaluation of turbine blades using Tomography are brought out.

C. Muralidhar; S. N. Lukose; M. P. Subramanian

2006-01-01T23:59:59.000Z

52

Seismic Tomography: Definitions Lapo Boschi (lapo@erdw.ethz.ch)  

E-Print Network [OSTI]

Seismic Tomography: Definitions Lapo Boschi (lapo@erdw.ethz.ch) September 14, 2009 Seismic Tomography Seismic tomography is the science of interpreting seismic measurements (seismograms) to derive information about the structure of the Earth. This course does not cover the techniques of seismic observation

Boschi, Lapo

53

Cone Beam Tomography using MPI on Heterogeneous Workstation Clusters  

E-Print Network [OSTI]

tomography is a computed tomography method which efficiently acquires projectional data through a single. Introduction Tomographic reconstruction from projections using computed tomography (CT) provides a noninvasive, the projectional data is projected back onto an image buffer with each de- tected ray backprojected in it

Chaudhary, Vipin

54

Improving Electrical Resistivity Tomography for Characterization of  

E-Print Network [OSTI]

Improving Electrical Resistivity Tomography for Characterization of Non-point Source Contaminants on the environment. Urban and agricultural runoff are often associated with an increase in water electrical conductivity. Although electrical conductivity (EC) cannot be used to identify individual chemical species

Fay, Noah

55

Binary Tomography with Deblurring Stefan Weber1  

E-Print Network [OSTI]

two scenarios of limited-angle binary tomography with data distorted with an unknown convolution: Either the projec- tion data are taken from a blurred object, or the projection data them- selves the projection data before reconstruction (let us call them preprocessing) and then the reconstruction

Schnörr, Christoph

56

Single-Shot Quantum Process Tomography  

E-Print Network [OSTI]

The standard procedure for quantum process tomography (QPT) involves applying the quantum process on a system initialized in each of a complete set of orthonormal states. The corresponding outputs are then characterized by quantum state tomography (QST), which itself requires the measurement of non-commuting observables realized by independent experiments on identically prepared system states. Thus QPT procedure demands a number of independent measurements, and moreover, this number increases rapidly with the size of the system. However, the total number of independent measurements can be greatly reduced with the availability of ancilla qubits. Ancilla assisted process tomography (AAPT) has earlier been shown to require a single QST of system-ancilla space. Ancilla assisted quantum state tomography (AAQST) has also been shown to perform QST in a single measurement. Here we combine AAPT with AAQST to realize a `single-shot QPT' (SSPT), a procedure to characterize a general quantum process in a single collective measurement of a set of commuting observables. We demonstrate experimental SSPT by characterizing several single-qubit processes using a three-qubit NMR quantum register. Furthermore, using the SSPT procedure we experimentally characterize the twirling process and compare the results with theory.

Abhishek Shukla; T. S. Mahesh

2014-05-27T23:59:59.000Z

57

AFIP-7 Tomography – 2013 Status Report  

SciTech Connect (OSTI)

This project seeks to assess the geometric stability of the U-Mo monolithic fuel system by evaluating the radiation-induced changes in the AFIP-7 experiment device. Neutron radiography and computed tomography (CT) provide valuable information about the post-irradiation condition of the fuel specimen. Tomographic reconstructions of the AFIP-7 fuel element will be analyzed to assess the geometric condition of the element after irradiation and provide information regarding the condition of the fuel, including gross geometric defects, bowing, twist, plate buckling, cracks, and other defects. The INL, in collaboration with Oregon State University (OSU), Missouri University of Science and Technology (Missouri S&T), and Real Time Tomography, is developing advanced neutron detector systems and tomographic reconstruction techniques to evaluate the AFIP-7 fuel element. Neutron computed tomography using the current neutron radiography technique available at the Neutron Radiography reactor (NRAD) is impractical due to the long time and high cost to produce a set of images for tomographic reconstruction. Advanced neutron radiography systems such as the micro-channel plate (MCP) detector and neutron computed radiography (CR) may reduce the time and cost of acquiring images for neutron CT.

A.E. Craft; W.J. Williams; M.I.K. Abir; D.M. Wachs

2013-10-01T23:59:59.000Z

58

Three-Dimensional Thermal Tomography Advances Cancer Treatment...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Three-Dimensional Thermal Tomography Advances Cancer Treatment Technology available for licensing: A 3D technique to detect early skin changes due to radiation treatment in breast...

59

angiographic computed tomography: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the development and application of a 4-Dimensional Computed Tomography (4D CT) simulation program. The simulation is used to understand and quantify the sources of image...

60

White-Etching Crack Failure Overview, Tomography Analysis, and...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

White-Etching Crack Failure Overview, Tomography Analysis, and Test Development Presented by Aaron Greco of Argonne National Laboratory at the Wind Turbine Tribology Seminar 2014....

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Time-dependent seismic tomography and its application to the...  

Open Energy Info (EERE)

changes in Earth structure are commonly determined using local earthquake tomography computer programs that invert multiple seismic-wave arrival time data sets separately and...

62

Instability of the linearized problem in multiwave tomography of ...  

E-Print Network [OSTI]

the sound speed and the thermal absorption arising in thermoacoustic and ... body of a patient, most often electromagnetic (thermoacoustic tomography) or op-

2013-10-03T23:59:59.000Z

63

Constrained optimization in seismic reflection tomography: an SQP ...  

E-Print Network [OSTI]

Seismic reflection tomography is a method for determining a subsurface velocity model from the traveltimes of seismic waves reflecting on geological interfaces.

2004-07-06T23:59:59.000Z

64

In-line x-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite-cementite microstructure in steel  

E-Print Network [OSTI]

In-line x-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite;In-line X-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite embedded in a ferrite matrix of medium-carbon steel. The measurements were carried out at the material

van Vliet, Lucas J.

65

28,183HUSEN ET AL.: TOMOGRAPHY OF SHALLOW SUBDUCTION IN CHILE Local earthquake tomography of shallow subduction in north Chile: A  

E-Print Network [OSTI]

[Graeber and Asch, 1999; C. Haberland and A. Rietbrock, Attenuation tomography in the western central Andes

Boschi, Lapo

66

Characterizing aquifer heterogeneity using hydraulic tomography  

E-Print Network [OSTI]

such as sands and gravels because these materials drain the water so quickly. The K value is highly localized and only represents the portion of the aquifer in which the core was taken. When working with unconsolidated sediments, care must be taken to pack...?????. .?????.1 17 vi LIST OF FIGURES Figure 1: Map of field site and layout of wells used in study (figure modified from Engard, 2006). Figure 2: MOG setup for tomography study. Figure 3: Packed versus unpacked response in an observation well...

Wachter, Brian James

2008-07-29T23:59:59.000Z

67

Adaptive schemes for incomplete quantum process tomography  

SciTech Connect (OSTI)

We propose an iterative algorithm for incomplete quantum process tomography with the help of quantum state estimation. The algorithm, which is based on the combined principles of maximum likelihood and maximum entropy, yields a unique estimator for an unknown quantum process when one has less than a complete set of linearly independent measurement data to specify the quantum process uniquely. We apply this iterative algorithm adaptively in various situations and so optimize the amount of resources required to estimate a quantum process with incomplete data.

Teo, Yong Siah [Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, Singapore 117597 (Singapore); Englert, Berthold-Georg [Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Rehacek, Jaroslav; Hradil, Zdenek [Department of Optics, Palacky University, 17. listopadu 12, CZ-77146 Olomouc (Czech Republic)

2011-12-15T23:59:59.000Z

68

E-Print Network 3.0 - angiography computed tomography Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Solutions Computed Tomography (CTCAT) 3D volume is reconstructed... ) Computer Tomography (CT): Radon-Transformation reconstructs images from projection data-profiles ...

69

XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale Particles. XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale Particles. Abstract: We present a...

70

E-Print Network 3.0 - artery computed tomography Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

computed tomography Search Powered by Explorit Topic List Advanced Search Sample search results for: artery computed tomography Page: << < 1 2 3 4 5 > >> 1 Abstract Computed...

71

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network [OSTI]

Multilevel bioluminescence tomography based on radiative transfer equation Part 2: total variation with both l1 and total- variation norm for bioluminescence tomography based on radiative transfer equation, Radiative Transfer (Dover Publications, 1960). 14. K. M. Case and P. F. PF Zweifel, Linear Transport Theory

Soatto, Stefano

72

Neutron Stimulated Emission Computed Tomography of Stable Isotopes  

E-Print Network [OSTI]

Neutron Stimulated Emission Computed Tomography of Stable Isotopes Carey E. Floyd Jr.*ab , Calvin North Carolina Keywords: imaging, neutrons, tomography, spectroscopy ABSTRACT Here we report on the development of a new molecular imaging technique using inelastic scattering of fast neutrons. Earlier studies

73

Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem  

SciTech Connect (OSTI)

Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.

William Charlton

2007-07-01T23:59:59.000Z

74

Total variation based Fourier reconstruction and regularization for computer tomography  

E-Print Network [OSTI]

of the reconstruted image. Insufficiency of data may be caused by the undersampling of projections, by the limitedTotal variation based Fourier reconstruction and regularization for computer tomography Xiao. Index Terms-- Computer tomography, reconstruction, regular- ization, iterative method, Fourier method

Zhang, Xiaoqun

75

Full-wavelet approach for fluorescence diffuse optical tomography  

E-Print Network [OSTI]

Full-wavelet approach for fluorescence diffuse optical tomography with structured illumination Leonardo da Vinci 32, I-20133 Milan, Italy 3 Centre for Medical Image Computing, University College London); published October 28, 2010 We present a fast reconstruction method for fluorescence optical tomography

Boyer, Edmond

76

Raw Data Compression in Computed Tomography: Noise Shaping  

E-Print Network [OSTI]

Raw Data Compression in Computed Tomography: Noise Shaping Yao Xie (team member: Adam Wang) Project.1 Background X-ray computed tomography (CT) builds on the physical principles of radiography. It uses multiple ring that has a limited data transfer rate. Compression can be used to reduce the data rate through

Xie, Yao

77

Propagation Beam Consideration for 3D THz Computed Tomography  

E-Print Network [OSTI]

Propagation Beam Consideration for 3D THz Computed Tomography B. Recur, 1, J.P. Guillet, 2 I. Manek, "Refraction losses in terahertz computed tomography," Opt. Commun. 283, 2050­2055 (2010). 8. S. Nadar, H, "Accelerated image reconstruction using ordered subsets of projection data," IEEE Trans. Med. Imaging 13, 601

Boyer, Edmond

78

Registration of Planar Film Radiographs with Computed Tomography  

E-Print Network [OSTI]

Registration of Planar Film Radiographs with Computed Tomography Lisa M. Gottesfeld Brown lisabHigh University Bethlehem, PA 18015 Abstract In this paper we describe a method to register Computed Tomography, high resolution, three dimensional, structural med- ical images, such as data from X-ray computed

Boult, Terrance E.

79

Double-Difference Tomography for Sequestration MVA  

SciTech Connect (OSTI)

Analysis of synthetic data was performed to determine the most cost-effective tomographic monitoring system for a geologic carbon sequestration injection site. Double-difference tomographic inversion was performed on 125 synthetic data sets: five stages of CO2 plume growth, five seismic event regions, and five geophone arrays. Each resulting velocity model was compared quantitatively to its respective synthetic velocity model to determine an accuracy value. The results were examined to determine a relationship between cost and accuracy in monitoring, verification, and accounting applications using double-difference tomography. The geophone arrays with widely-varying geophone locations, both laterally and vertically, performed best. Additionally, double difference seismic tomography was performed using travel time data from a carbon sequestration site at the Aneth oil field in southeast Utah as part of a Department of Energy initiative on monitoring, verification, and accounting (MVA) of sequestered CO2. A total of 1,211 seismic events were recorded from a borehole array consisting of 22 geophones. Artificial velocity models were created to determine the ease with which different CO2 plume locations and sizes can be detected. Most likely because of the poor geophone arrangement, a low velocity zone in the Desert Creek reservoir can only be detected when regions of test site containing the highest ray path coverage are considered. MVA accuracy and precision may be improved through the use of a receiver array that provides more comprehensive ray path coverage.

Westman, Erik

2008-12-31T23:59:59.000Z

80

Compact conscious animal positron emission tomography scanner  

DOE Patents [OSTI]

A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

Schyler, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY); Volkow, Nora (Chevy Chase, MD)

2006-10-24T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Ultra-high resolution computed tomography imaging  

DOE Patents [OSTI]

A method for ultra-high resolution computed tomography imaging, comprising the steps of: focusing a high energy particle beam, for example x-rays or gamma-rays, onto a target object; acquiring a 2-dimensional projection data set representative of the target object; generating a corrected projection data set by applying a deconvolution algorithm, having an experimentally determined a transfer function, to the 2-dimensional data set; storing the corrected projection data set; incrementally rotating the target object through an angle of approximately 180.degree., and after each the incremental rotation, repeating the radiating, acquiring, generating and storing steps; and, after the rotating step, applying a cone-beam algorithm, for example a modified tomographic reconstruction algorithm, to the corrected projection data sets to generate a 3-dimensional image. The size of the spot focus of the beam is reduced to not greater than approximately 1 micron, and even to not greater than approximately 0.5 microns.

Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Knoxville, TN); Tobin, Jr., Kenneth William (Harriman, TN); Gleason, Shaun S. (Knoxville, TN); Thomas, Jr., Clarence E. (Knoxville, TN)

2002-01-01T23:59:59.000Z

82

Performance dependence of hybrid x-ray computed tomography/fluorescence molecular  

E-Print Network [OSTI]

Performance dependence of hybrid x-ray computed tomography/fluorescence molecular tomography imaging systems combining x-ray computed tomography (CT) and fluorescence tomography can im- prove Ntziachristos2 1 Department of Electrical and Computer Engineering, Northeastern University, 360 Huntington Ave

Miller, Eric

83

Magnified Weak Lensing Cross Correlation Tomography  

SciTech Connect (OSTI)

This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60 nights on 4-m class telescopes, which gives concrete evidence of strong community support for this project. The WLT technique is based on the dependence of the gravitational shear signal on the angular diameter distances between the observer, the lens, and the lensed galaxy to measure cosmological parameters. By taking the ratio of measured shears of galaxies with different redshifts around the same lens, one obtains a measurement of the ratios of the angular diameter distances involved. Making these observations over a large range of lenses and background galaxy redshifts will measure the history of the expansion rate of the universe. Because this is a purely geometric measurement, it is insensitive to any form of evolution of objects or the necessity to understand the physics in the early universe. Thus, WLT was identified by the Dark Energy Task Force as perhaps the best method to measure the evolution of DE. To date, however, the conjecture of the DETF has not been experimentally verified, but will be by the proposed project. The primary reason for the lack of tomography measurements is that one must have an exceptional data-set to attempt the measurement. One needs both extremely good seeing (or space observations) in order to minimize the point spread function smearing corrections on weak lensing shear measurements and deep, multi-color data, from B to z, to measure reliable photometric redshifts of the background galaxies being lensed (which are typically too faint to obtain spectroscopic redshifts). Because the entire process from multi-drizzling the HST images, and then creating shear maps, to gathering the necessary ground based observations, to generating photo-zs and then carrying out the tomography is a complicated task, until the creation of our team, nobody has taken the time to connect all the levels of expertise necessary to carry out this project based on HST archival data. Our data are being used in 2 Ph.D. theses. Kellen Murphy, at Ohio University, is using the tomography data along with simulations in a thesis expected to be completed in Jun

Ulmer, Melville P., Clowe, Douglas I.

2010-11-30T23:59:59.000Z

84

Embrittlement of RPV steels; An atom probe tomography perspective  

SciTech Connect (OSTI)

Atom probe tomography has played a key role in the understanding of the embrittlement of neutron irradiated reactor pressure vessel steels through the atomic level characterization of the microstructure. Atom probe tomography has been used to demonstrate the importance of the post weld stress relief treatment in reducing the matrix copper content in high copper alloys, the formation of {approx}-nm-diameter copper-, nickel-, manganese- and silicon-enriched precipitates during neutron irradiation in copper containing RPV steels, and the coarsening of these precipitates during post irradiation heat treatments. Atom probe tomography has been used to detect {approx}2-nm-diameter nickel-, silicon- and manganese-enriched clusters in neutron irradiated low copper and copper free alloys. Atom probe tomography has also been used to quantify solute segregation to, and precipitation on, dislocations and grain boundaries.

Miller, Michael K [ORNL; Russell, Kaye F [ORNL

2007-01-01T23:59:59.000Z

85

Functional lung imaging in humans using Positron Emission Tomography  

E-Print Network [OSTI]

This thesis deals with a method of functional lung imaging using Positron Emission Tomography (PET). In this technique, a radioactive tracer, nitrogen-13, is dissolved in saline solution, and injected into a peripheral ...

Layfield, Dominick, 1971-

2003-01-01T23:59:59.000Z

86

Scattered neutron tomography based on a neutron transport problem  

E-Print Network [OSTI]

scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

Scipolo, Vittorio

2005-11-01T23:59:59.000Z

87

Breast ultrasound tomography with total-variation regularization  

SciTech Connect (OSTI)

Breast ultrasound tomography is a rapidly developing imaging modality that has the potential to impact breast cancer screening and diagnosis. A new ultrasound breast imaging device (CURE) with a ring array of transducers has been designed and built at Karmanos Cancer Institute, which acquires both reflection and transmission ultrasound signals. To extract the sound-speed information from the breast data acquired by CURE, we have developed an iterative sound-speed image reconstruction algorithm for breast ultrasound transmission tomography based on total-variation (TV) minimization. We investigate applicability of the TV tomography algorithm using in vivo ultrasound breast data from 61 patients, and compare the results with those obtained using the Tikhonov regularization method. We demonstrate that, compared to the Tikhonov regularization scheme, the TV regularization method significantly improves image quality, resulting in sound-speed tomography images with sharp (preserved) edges of abnormalities and few artifacts.

Huang, Lianjie [Los Alamos National Laboratory; Li, Cuiping [KARMANOS CANCER INSTIT.; Duric, Neb [KARMANOS CANCER INSTIT

2009-01-01T23:59:59.000Z

88

Computational Inversion of Electron Tomography Images -Gradient Flows  

E-Print Network [OSTI]

Computational Inversion of Electron Tomography Images Using L2 -Gradient Flows Guoliang Xu 1) Ming Computing Institute of Computational Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100190, China 2) Department of Computer Sciences and Institute

Texas at Austin, University of

89

A Detector for Proton Computed Tomography  

SciTech Connect (OSTI)

Radiation therapy is a widely recognized treatment for cancer. Energetic protons have distinct features that set them apart from photons and make them desirable for cancer therapy as well as medical imaging. The clinical interest in heavy ion therapy is due to the fact that ions deposit almost all of their energy in a sharp peak – the Bragg peak- at the very end of their path. Proton beams can be used to precisely localize a tumor and deliver an exact dose to the tumor with small doses to the surrounding tissue. Proton computed tomography (pCT) provides direct information on the location on the target tumor, and avoids position uncertainty caused by treatment planning based on imaging with X-ray CT. The pCT project goal is to measure and reconstruct the proton relative stopping power distribution directly in situ. To ensure the full advantage of cancer treatment with 200 MeV proton beams, pCT must be realized.

Blazey, G.; et al.,

2013-12-06T23:59:59.000Z

90

Nonlinear regularization techniques for seismic tomography  

SciTech Connect (OSTI)

The effects of several nonlinear regularization techniques are discussed in the framework of 3D seismic tomography. Traditional, linear, l{sub 2} penalties are compared to so-called sparsity promoting l{sub 1} and l{sub 0} penalties, and a total variation penalty. Which of these algorithms is judged optimal depends on the specific requirements of the scientific experiment. If the correct reproduction of model amplitudes is important, classical damping towards a smooth model using an l{sub 2} norm works almost as well as minimizing the total variation but is much more efficient. If gradients (edges of anomalies) should be resolved with a minimum of distortion, we prefer l{sub 1} damping of Daubechies-4 wavelet coefficients. It has the additional advantage of yielding a noiseless reconstruction, contrary to simple l{sub 2} minimization ('Tikhonov regularization') which should be avoided. In some of our examples, the l{sub 0} method produced notable artifacts. In addition we show how nonlinear l{sub 1} methods for finding sparse models can be competitive in speed with the widely used l{sub 2} methods, certainly under noisy conditions, so that there is no need to shun l{sub 1} penalizations.

Loris, I. [Mathematics Department, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium)], E-mail: igloris@vub.ac.be; Douma, H. [Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, NJ 08544 (United States); Nolet, G. [Geosciences Azur, Universite de Nice-Sophia Antipolis, CNRS/IRD, 250 Rue Albert Einstein, Sophia Antipolis 06560 (France); Daubechies, I. [Program in Applied and Computational Mathematics, Princeton University, Fine Hall, Washington Road, Princeton, NJ 08544 (United States); Regone, C. [BP America Inc., 501 Westlake Park Blvd., Houston, TX 77079 (United States)

2010-02-01T23:59:59.000Z

91

Portable Digital Radiography and Computed Tomography Manual  

SciTech Connect (OSTI)

This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

Not Available

2007-11-01T23:59:59.000Z

92

Quantum tomography with wavelet transform in Banach space on Homogeneous space  

E-Print Network [OSTI]

The intimate connection between the Banach space wavelet reconstruction method on homogeneous spaces with both singular and nonsingular vacuum vectors, and some of well known quantum tomographies, such as: Moyal-representation for a spin, discrete phase space tomography, tomography of a free particle, Homodyne tomography, phase space tomography and SU(1,1) tomography is explained. Also both the atomic decomposition and banach frame nature of these quantum tomographic examples is explained in details. Finally the connection between the wavelet formalism on Banach space and Q-function is discussed.

M. A. Jafarizadeh; M. Mirzaee; M. Rezaee

2008-01-25T23:59:59.000Z

93

State Waste Discharge Permit Application: Electric resistance tomography testing  

SciTech Connect (OSTI)

This permit application documentation is for a State Waste Discharge Permit issued in accordance with requirements of Washington Administrative Code 173-216. The activity being permitted is a technology test using electrical resistance tomography. The electrical resistance tomography technology was developed at Lawrence Livermore National Laboratory and has been used at other waste sites to track underground contamination plumes. The electrical resistance tomography technology measures soil electrical resistance between two electrodes. If a fluid contaminated with electrolytes is introduced into the soil, the soil resistance is expected to drop. By using an array of measurement electrodes in several boreholes, the areal extent of contamination can be estimated. At the Hanford Site, the purpose of the testing is to determine if the electrical resistance tomography technology can be used in the vicinity of large underground metal tanks without the metal tank interfering with the test. It is anticipated that the electrical resistance tomography technology will provide a method for accurately detecting leaks from the bottom of underground tanks, such as the Hanford Site single-shell tanks.

Not Available

1994-04-01T23:59:59.000Z

94

Dictionary-Learning-Based Reconstruction Method for Electron Tomography  

E-Print Network [OSTI]

Electron tomography usually suffers from so called missing wedge artifacts caused by limited tilt angle range. An equally sloped tomography (EST) acquisition scheme (which should be called the linogram sampling scheme) was recently applied to achieve 2.4-angstrom resolution. On the other hand, a compressive sensing-inspired reconstruction algorithm, known as adaptive dictionary based statistical iterative reconstruction (ADSIR), has been reported for x-ray computed tomography. In this paper, we evaluate the EST, ADSIR and an ordered-subset simultaneous algebraic reconstruction technique (OS-SART), and compare the ES and equally angled (EA) data acquisition modes. Our results show that OS-SART is comparable to EST, and the ADSIR outperforms EST and OS-SART. Furthermore, the equally sloped projection data acquisition mode has no advantage over the conventional equally angled mode in the context.

Liu, Baodong; Verbridge, Scott S; Sun, Lizhi; Wang, Ge

2013-01-01T23:59:59.000Z

95

E-Print Network 3.0 - agent-enhanced computed tomography Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

computed tomography Page: << < 1 2 3 4 5 > >> 1 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

96

E-Print Network 3.0 - advanced computed tomography Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

advanced computed tomography Page: << < 1 2 3 4 5 > >> 1 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

97

Quantum Process Tomography by 2D Fluorescence Spectroscopy  

E-Print Network [OSTI]

Reconstruction of the dynamics (quantum process tomography) of the single-exciton manifold in energy transfer systems is proposed here on the basis of two-dimensional fluorescence spectroscopy (2D-FS) with phase-modulation. The quantum-process-tomography protocol introduced here benefits from, e.g., the sensitivity enhancement and signal-to-noise ratio ascribed to 2D-FS. Although the isotropically averaged spectroscopic signals depend on the quantum yield parameter $\\Gamma$ of the doubly-excited-exciton manifold, it is shown that the reconstruction of the dynamics is insensitive to this parameter. Applications to foundational and applied problems, as well as further extensions, are discussed.

Leonardo A. Pachon; Andrew H. Marcus; Alan Aspuru-Guzik

2015-02-09T23:59:59.000Z

98

Quantum Process Tomography by 2D Fluorescence Spectroscopy  

E-Print Network [OSTI]

Reconstruction of the dynamics (quantum process tomography) of the single-exciton manifold in energy transfer systems is proposed here on the basis of two-dimensional fluorescence spectroscopy (2D-FS) with phase-modulation. The quantum-process-tomography protocol introduced here benefits from, e.g., the sensitivity enhancement and signal-to-noise ratio ascribed to 2D-FS. Although the isotropically averaged spectroscopic signals depend on the quantum yield parameter $\\Gamma$ of the doubly-excited-exciton manifold, it is shown that the reconstruction of the dynamics is insensitive to this parameter. Applications to foundational and applied problems, as well as further extensions, are discussed.

Pachon, Leonardo A; Aspuru-Guzik, Alan

2015-01-01T23:59:59.000Z

99

Multiplexed absorption tomography with calibration-free wavelength modulation spectroscopy  

SciTech Connect (OSTI)

We propose a multiplexed absorption tomography technique, which uses calibration-free wavelength modulation spectroscopy with tunable semiconductor lasers for the simultaneous imaging of temperature and species concentration in harsh combustion environments. Compared with the commonly used direct absorption spectroscopy (DAS) counterpart, the present variant enjoys better signal-to-noise ratios and requires no baseline fitting, a particularly desirable feature for high-pressure applications, where adjacent absorption features overlap and interfere severely. We present proof-of-concept numerical demonstrations of the technique using realistic phantom models of harsh combustion environments and prove that the proposed techniques outperform currently available tomography techniques based on DAS.

Cai, Weiwei; Kaminski, Clemens F., E-mail: cfk23@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 3RA (United Kingdom)

2014-04-14T23:59:59.000Z

100

Quantum Process Tomography via L1-norm Minimization  

E-Print Network [OSTI]

For an initially well designed but imperfect quantum information system, the process matrix is almost sparse in an appropriate basis. Existing theory and associated computational methods (L1-norm minimization) for reconstructing sparse signals establish conditions under which the sparse signal can be perfectly reconstructed from a very limited number of measurements (resources). Although a direct extension to quantum process tomography of the L1-norm minimization theory has not yet emerged, the numerical examples presented here, which apply L1-norm minimization to quantum process tomography, show a significant reduction in resources to achieve a desired estimation accuracy over existing methods.

Robert L. Kosut

2009-03-05T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Quantitative electron holographic tomography for the 3D characterisation of semiconductor device structures  

E-Print Network [OSTI]

Quantitative electron holographic tomography for the 3D characterisation of semiconductor device tomography Silicon devices Device characterisation a b s t r a c t Electron tomography and electron rights reserved. 1. Introduction Dopant profiling of semiconductor devices using off-axis electron

Dunin-Borkowski, Rafal E.

102

LimitedAngle Computed Tomography for Sandwich Structures using Data Fusion  

E-Print Network [OSTI]

1 Limited­Angle Computed Tomography for Sandwich Structures using Data Fusion Jeffrey E. Boyd and limited­angle computed­tomography (CT) are ill­posed problems, but where conventional CT has a small null. #12; 2 1. INTRODUCTION This paper presents a novel method for limited­angle computed tomography (CT

Boyd, Jeffrey E.

103

Reduction of Metal Artifacts in Computed Tomographies for the Planning and Simulation of Radiation Therapy  

E-Print Network [OSTI]

tomographies (CT). Compared to simulated CT projection data, real measurements allowed less improvementsReduction of Metal Artifacts in Computed Tomographies for the Planning and Simulation of Radiation and numerical stability. 1. INTRODUCTION In radiation therapy, computed tomographies are used for patient

Zerfowski, Detlef

104

Robust statistical reconstruction for charged particle tomography  

DOE Patents [OSTI]

Systems and methods for charged particle detection including statistical reconstruction of object volume scattering density profiles from charged particle tomographic data to determine the probability distribution of charged particle scattering using a statistical multiple scattering model and determine a substantially maximum likelihood estimate of object volume scattering density using expectation maximization (ML/EM) algorithm to reconstruct the object volume scattering density. The presence of and/or type of object occupying the volume of interest can be identified from the reconstructed volume scattering density profile. The charged particle tomographic data can be cosmic ray muon tomographic data from a muon tracker for scanning packages, containers, vehicles or cargo. The method can be implemented using a computer program which is executable on a computer.

2013-10-08T23:59:59.000Z

105

USING OPTICAL COHERENCE TOMOGRAPHY TO EXAMINE THE SUBSURFACE MORPHOLOGY OF  

E-Print Network [OSTI]

: (1) a homogeneous glassy phase; (2) a liquid­liquid phase separated state; and (3) a crystallizedUSING OPTICAL COHERENCE TOMOGRAPHY TO EXAMINE THE SUBSURFACE MORPHOLOGY OF CHINESE GLAZES M of their glazes. The images revealed unique phase assemblage modes in different samples. The results suggest

Barton, Jennifer K.

106

Adaptive optics enhanced simultaneous en-face optical coherence tomography  

E-Print Network [OSTI]

Adaptive optics enhanced simultaneous en-face optical coherence tomography and scanning laser ophthalmoscopy David Merino and Chris Dainty Applied Optics Group, Department of Experimental Physics, National and Adrian Gh. Podoleanu Applied Optics Group, School of Physical Sciences, University of Kent at Canterbury

Dainty, Chris

107

Cone-based electrical resistivity tomography Adam Pidlisecky1  

E-Print Network [OSTI]

Cone-based electrical resistivity tomography Adam Pidlisecky1 , Rosemary Knight1 , and Eldad Haber2 that can provide information about the 3D distribu- tion of electrical conductivity. The technique, cone-bert method. C-bert data are inverted using an inexact Gauss-Newton algorithm to produce a 3D electrical

Knight, Rosemary

108

Microwave-induced thermoacoustic tomography: reconstruction by synthetic aperture  

E-Print Network [OSTI]

-induced thermoacoustic tomography (LMTT) based on focused transducers. Two microwave sources, which had frequencies of 9 GHz and 3 GHz, respectively, were used in the experiments for comparison. The 3-GHz system had a much larger imaging depth but a lower signal...

Feng, Dazi

2001-01-01T23:59:59.000Z

109

3D Tomography from Few Projections in Experimental Fluid Dynamics  

E-Print Network [OSTI]

3D Tomography from Few Projections in Experimental Fluid Dynamics Stefania Petra, Andreas Schr projections due to both limited optical access to wind and water tunnels and cost S. Petra, C. Schn projection data. The latter are the pixel entries in the recorded 2D images that represent the integration

Schnörr, Christoph

110

Volumetric Reconstruction in the MicroCAT Tomography System  

E-Print Network [OSTI]

of projection data . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.2 Illustration of Feldkamp filteredVolumetric Reconstruction in the MicroCAT Tomography System A Thesis Presented for the Master essential data and an intimate knowledge of the MicroCAT system. Dr. Sam Jordan of the University

Cates, Josh

111

Bayesian Image Reconstruction for Transmission Tomography Using Deterministic Annealing  

E-Print Network [OSTI]

and non-medical applications, however, the measured projection data are photon limited and the imaging;1 INTRODUCTION Transmission tomography is perhaps most familiar in its medical guise as CT (computed tomogra- phy procedure. Because of the relatively high dose in conventional CT, the measured projection data contain

Rangarajan, Anand

112

Insights into the structure of the upper mantle beneath the Murray Basin from 3D teleseismic tomography  

E-Print Network [OSTI]

tomography studies have been carried out in western Victoria (Graeber et al. 2002) and northern Tasmania

Rawlinson, Nick

113

Quantum tomography meets dynamical systems and bifurcations theory  

SciTech Connect (OSTI)

A powerful tool for studying geometrical problems in Hilbert spaces is developed. We demonstrate the convergence and robustness of our method in every dimension by considering dynamical systems theory. This method provides numerical solutions to hard problems involving many coupled nonlinear equations in low and high dimensions (e.g., quantum tomography problem, existence and classification of Pauli partners, mutually unbiased bases, complex Hadamard matrices, equiangular tight frames, etc.). Additionally, this tool can be used to find analytical solutions and also to implicitly prove the existence of solutions. Here, we develop the theory for the quantum pure state tomography problem in finite dimensions but this approach is straightforwardly extended to the rest of the problems. We prove that solutions are always attractive fixed points of a nonlinear operator explicitly given. As an application, we show that the statistics collected from three random orthonormal bases is enough to reconstruct pure states from experimental (noisy) data in every dimension d ? 32.

Goyeneche, D., E-mail: dardo.goyeneche@cefop.udec.cl [Departamento de Fisíca, Universidad de Concepción, Casilla 160-C, Concepción, Chile and Center for Optics and Photonics, Universidad de Concepción, Casilla 4012, Concepción (Chile); Torre, A. C. de la [Departamento de Física, Universidad Nacional de Mar del Plata, IFIMAR-CONICET, Dean Funes 3350, 7600 Mar del Plata (Argentina)

2014-06-15T23:59:59.000Z

114

Using electrical impedance tomography to map subsurface hydraulic conductivity  

DOE Patents [OSTI]

The use of Electrical Impedance Tomography (EIT) to map subsurface hydraulic conductivity. EIT can be used to map hydraulic conductivity in the subsurface where measurements of both amplitude and phase are made. Hydraulic conductivity depends on at least two parameters: porosity and a length scale parameter. Electrical Resistance Tomography (ERT) measures and maps electrical conductivity (which can be related to porosity) in three dimensions. By introducing phase measurements along with amplitude, the desired additional measurement of a pertinent length scale can be achieved. Hydraulic conductivity controls the ability to flush unwanted fluid contaminants from the surface. Thus inexpensive maps of hydraulic conductivity would improve planning strategies for subsequent remediation efforts. Fluid permeability is also of importance for oil field exploitation and thus detailed knowledge of fluid permeability distribution in three-dimension (3-D) would be a great boon to petroleum reservoir analysts.

Berryman, James G. (Danville, CA); Daily, William D. (Livermore, CA); Ramirez, Abelardo L. (Pleasanton, CA); Roberts, Jeffery J. (Livermore, CA)

2000-01-01T23:59:59.000Z

115

Systematic errors in current quantum state tomography tools  

E-Print Network [OSTI]

Common tools for obtaining physical density matrices in experimental quantum state tomography are shown here to cause systematic errors. For example, using maximum likelihood or least squares optimization for state reconstruction, we observe a systematic underestimation of the fidelity and an overestimation of entanglement. A solution for this problem can be achieved by a linear evaluation of the data yielding reliable and computational simple bounds including error bars.

Christian Schwemmer; Lukas Knips; Daniel Richart; Tobias Moroder; Matthias Kleinmann; Otfried Gühne; Harald Weinfurter

2014-07-22T23:59:59.000Z

116

Photoacoustic computed tomography in biological tissues: algorithms and breast imaging  

E-Print Network [OSTI]

are investigated in Chapter III and IV, respectively. Finally, a prototype of an RF-induced PA imaging system is introduced and experiments using phantom samples as well as a preliminary study of breast imaging for cancer detection are reported in Chapter V... PHOTOACOUSTIC COMPUTED TOMOGRAPHY IN BIOLOGICAL TISSUES: ALGORITHMS AND BREAST IMAGING A Dissertation by MINGHUA XU Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...

Xu, Minghua

2004-11-15T23:59:59.000Z

117

?A cylindrical specimen holder for electron cryo-tomography  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . 57 3.6 Characterisation of carbon nanopipettes . . . . . . . . . . . . . . . . 59 3.7 Discussion of the manufacturing process . . . . . . . . . . . . . . . . 63 4 Cryo-tomography 67 4.1 Specimen preparation I... . . . . . . . . . . . . . . . . . 60 3.7 Elemental maps and longitudinal EDX linescan of a carbon nanopipette 61 3.8 Transverse EDX linescan of a carbon nanopipette . . . . . . . . . . . 62 4.1 Transmission electron micrograph of a blocked carbon nanopipette tip 68 4.2 A carbon...

Palmer, Colin Michael

2013-03-12T23:59:59.000Z

118

Coral Extension Rate Analysis Using Computed Axial Tomography  

E-Print Network [OSTI]

CORAL EXTENSION RATE ANALYSIS USING COMPUTED AXIAL TOMOGRAPHY A Thesis by ELEANOR ANN YUDELMAN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE Chair of Committee, Niall Slowey Committee Members, Deborah Thomas Benjamin Giese George P. Schmahl Head of Department, Deborah Thomas May 2014 Major Subject: Oceanography Copyright 2014 Eleanor Ann Yudelman ii ABSTRACT...

Yudelman, Eleanor Ann

2014-01-10T23:59:59.000Z

119

Recent developments in guided wave travel time tomography  

SciTech Connect (OSTI)

The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections. Guided wave tomography had been developed to create a map of the wall thickness using the travel times of guided waves. It can be used for both monitoring and for inspection of pipe-segments that are difficult to access, for instance at the location of pipe-supports. An important outcome of the tomography is the minimum remaining wall thickness, as this is critical in the scheduling of a replacement of the pipe-segment. In order to improve the sizing accuracy we have improved the tomography scheme. A number of major improvements have been realized allowing to extend the application envelope to pipes with a larger wall thickness and to larger distances between the transducer rings. Simulation results indicate that the sizing accuracy has improved and that is now possible to have a spacing of 8 meter between the source-ring and the receiver-ring. Additionally a reduction of the number of sensors required might be possible as well.

Zon, Tim van; Volker, Arno [TNO, Stieltjesweg 1, P.O. box 155 2600 AD Delft (Netherlands)

2014-02-18T23:59:59.000Z

120

E-Print Network 3.0 - aids computed tomography Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Mathematics, Tufts University Collection: Mathematics 2 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

E-Print Network 3.0 - attenuated vector tomography Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Kansas State University Collection: Mathematics 2 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: Optical Tomography Novel...

122

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

with Additional Information Additional information about the non-medical uses of nuclear imaging, computed tomography, and non-destructive testing is available in DOE...

123

E-Print Network 3.0 - abdominal computed tomography Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

aortic aneurysm (AAA) from computed tomography angiography (CTA) images. Output data (3-D model) form... angiography (DSA), computed ... Source: Loncaric, Sven - Faculty of...

124

Software-defined Radio Based Wireless Tomography: Experimental Demonstration and Verification  

SciTech Connect (OSTI)

This letter presents an experimental demonstration of software-defined-radio-based wireless tomography using computer-hosted radio devices called Universal Software Radio Peripheral (USRP). This experimental brief follows our vision and previous theoretical study of wireless tomography that combines wireless communication and RF tomography to provide a novel approach to remote sensing. Automatic data acquisition is performed inside an RF anechoic chamber. Semidefinite relaxation is used for phase retrieval, and the Born iterative method is utilized for imaging the target. Experimental results are presented, validating our vision of wireless tomography.

Bonior, Jason D [ORNL; Hu, Zhen [Tennessee Technological University; Guo, Terry N. [Tennessee Technological University; Qiu, Robert C. [Tennessee Technological University; Browning, James P. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Wicks, Michael C. [University of Dayton Research Institute

2015-01-01T23:59:59.000Z

125

3D Reconstruction of Intricate Archean Microbial Structures Using Neutron Computed Tomography and Serial SectioningIN43B-0331 Abstract Project Goals  

E-Print Network [OSTI]

Tomography and Serial SectioningIN43B-0331 Abstract Project Goals Background Methods Neutron Computed using both serial sectioning and neutron computed tomography (NCT). Reconstruction techniques vary mechanisms for ancient microbial communities Neutron Computed Tomography Serial Sectioning Samples were

Hamann, Bernd

126

Remote Tomography Via von Neumann-Arthurs-Kelly Interaction  

E-Print Network [OSTI]

Teleportation usually involves entangled particles 1,2 shared by Alice and Bob, Bell-state measurement on particle 1 and system particle by Alice, classical communication to Bob, and unitary transformation by Bob on particle 2. We propose a novel method: interaction-based remote tomography. Alice arranges an entanglement generating von Neumann-Arthurs-Kelly interaction between the system and two apparatus particles, and then teleports the latter to Bob. Bob reconstructs the unknown initial state of the system not received by him by quadrature measurements on the apparatus particles .

S. M. Roy; Abhinav Deshpande; Nitica Sakharwade

2013-08-23T23:59:59.000Z

127

Pulsed homodyne Gaussian quantum tomography with low detection efficiency  

E-Print Network [OSTI]

Pulsed homodyne quantum tomography usually requires a high detection efficiency limiting its applicability in quantum optics. Here, it is shown that the presence of low detection efficiency ($<50\\%$) does not prevent the tomographic reconstruction of quantum states of light, specifically, of Gaussian type. This result is obtained by applying the so-called "minimax" adaptive reconstruction of the Wigner function to pulsed homodyne detection. In particular, we prove, by both numerical and real experiments, that an effective discrimination of different Gaussian quantum states can be achieved. Our finding paves the way to a more extensive use of quantum tomographic methods, even in physical situations in which high detection efficiency is unattainable.

Martina Esposito; Fabio Benatti; Roberto Floreanini; Stefano Olivares; Francesco Randi; Kelvin Titimbo; Marco Pividori; Fabio Novelli; Federico Cilento; Fulvio Parmigiani; Daniele Fausti

2014-02-19T23:59:59.000Z

128

Tomography increases key rates of quantum-key-distribution protocols  

E-Print Network [OSTI]

We construct a practically implementable classical processing for the BB84 protocol and the six-state protocol that fully utilizes the accurate channel estimation method, which is also known as the quantum tomography. Our proposed processing yields at least as high key rate as the standard processing by Shor and Preskill. We show two examples of quantum channels over which the key rate of our proposed processing is strictly higher than the standard processing. In the second example, the BB84 protocol with our proposed processing yields a positive key rate even though the so-called error rate is higher than the 25% limit.

Shun Watanabe; Ryutaroh Matsumoto; Tomohiko Uyematsu

2008-07-22T23:59:59.000Z

129

Localization of Competing Metals (Ni, Co, and Zn) in Alyssum using micro-XRF and Tomography. (3564)  

E-Print Network [OSTI]

Localization of Competing Metals (Ni, Co, and Zn) in Alyssum using micro-XRF and Tomography. (3564 and observed metal localization in root and shoot tissue using synchrotron based micro-XRF and tomography

Sparks, Donald L.

130

Analysis of hydraulic tomography using temporal moments of drawdown recovery data  

E-Print Network [OSTI]

Analysis of hydraulic tomography using temporal moments of drawdown recovery data Junfeng Zhu 2006. [1] Transient hydraulic tomography (THT) is a potentially cost-effective and high- resolution technique for mapping spatial distributions of the hydraulic conductivity and specific storage in aquifers

Daniels, Jeffrey J.

131

Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping/observation densities  

E-Print Network [OSTI]

Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping August 2013; accepted 7 September 2013; published 13 November 2013. [1] 3-D Hydraulic tomography (3-D HT (primarily hydraulic conductivity, K) is estimated by joint inversion of head change data from multiple

Barrash, Warren

132

Electrical impedance tomography and Calderon's Department of Mathematics, University of Washington, Seattle, WA 98195, USA  

E-Print Network [OSTI]

Electrical impedance tomography and Calder´on's problem G Uhlmann Department of Mathematics, University of Washington, Seattle, WA 98195, USA E-mail: gunther@math.washington.edu Abstract. We survey mathematical developments in the inverse method of Electrical Impedance Tomography which consists

Uhlmann, Gunther

133

WIND TOMOGRAPHY IN BINARY SYSTEMS O.Knill, R.Dgani and M.Vogel  

E-Print Network [OSTI]

WIND TOMOGRAPHY IN BINARY SYSTEMS O.Knill, R.Dgani and M.Vogel ETH-Zurich, CH-8092, Switzerland method is particularly suitable for determining the velocity laws of stellar winds. 1. WIND TOMOGRAPHY AND ABEL'S INTEGRAL Binary systems in which a compact, point-like radiation source shines through the wind

Knill, Oliver

134

High-Resolution Optical Coherence Tomography-Guided Laser Ablation of Surgical Tissue1  

E-Print Network [OSTI]

High-Resolution Optical Coherence Tomography-Guided Laser Ablation of Surgical Tissue1 Stephen A Hospital, Boston, Massachusetts 02114 Submitted for publication September 17, 1998 Background. Optical coherence tomography (OCT) is a compact high-speed imaging technology which uses infrared light to acquire

Boppart, Stephen

135

3-D Electrical Resistivity Tomography for Cliff Stability Assessment at Pointe du Hoc in Normandy, France  

E-Print Network [OSTI]

purposes. The objective of this study is to apply advanced 3?D resistivity tomography toward a detailed site stability assessment with special attention to the two at-risk buildings. 3?D resistivity tomography datasets at Pointe du Hoc in the presence...

Udphuay, Suwimon

2010-01-14T23:59:59.000Z

136

Cloud tomography: Role of constraints and a new algorithm Dong Huang,1  

E-Print Network [OSTI]

Cloud tomography: Role of constraints and a new algorithm Dong Huang,1 Yangang Liu,1 and Warren 2008. [1] Retrieving spatial distributions of cloud liquid water content from limited-angle emission data (passive microwave cloud tomography) is ill-posed, and a small inaccuracy in the data and

137

Determining both sound speed and internal source in thermo- and photo-acoustic tomography  

E-Print Network [OSTI]

This paper concerns thermoacoustic tomography and photoacoustic tomography, two couple-physics imaging modalities that attempt to combine the high resolution of ultrasound and the high contrast capabilities of electromagnetic waves. We give sufficient conditions to recover both the sound speed of the medium being probed and the source.

Hongyu Liu; Gunther Uhlmann

2015-02-04T23:59:59.000Z

138

STUDY OF TRANS-RECTAL NEAR-INFRARED DIFFUSE OPTICAL TOMOGRAPHY CONCURRENT  

E-Print Network [OSTI]

STUDY OF TRANS-RECTAL NEAR-INFRARED DIFFUSE OPTICAL TOMOGRAPHY CONCURRENT WITH TRANS of the requirements for the Degree of DOCTOR OF PHILOSOPHY May, 2010 #12;ii STUDY OF TRANS-RECTAL NEAR-INFRARED supported by the project Trans-rectal Near-Infrared Optical Tomography for Prostate Imaging from DOD

Piao, Daqing

139

Using computerized tomography to determine ionospheric structures. Part 1, Notivation and basic approaches  

SciTech Connect (OSTI)

Properties of the ionosphere are reviewed along with its correlations with other geophysical phenomena and with applications of ionospheric studies to communication, navigation, and surveillance systems. Computer tomography is identified as a method to determine the detailed, three-dimensional distribution of electron density within the ionosphere. Several tomography methods are described, with a basic approach illustrated by an example. Limitations are identified.

Vittitoe, C.N.

1993-08-01T23:59:59.000Z

140

1996 InternationalConference on Parallel Processing PARALLEL IMPLEMENTATION OF CONE BEAM TOMOGRAPHY  

E-Print Network [OSTI]

projections us- ing computed tomography (CT) is the noninvasive measure of structure from external as follows: A. Weight projection data B. Convolve weighted projection data Pe*(u,v) = P&L, U) * h(u) C1996 InternationalConference on Parallel Processing PARALLEL IMPLEMENTATION OF CONE BEAM TOMOGRAPHY

Chaudhary, Vipin

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Spatially-Adaptive Reconstruction in Computed Tomography Based on Statistical Learning  

E-Print Network [OSTI]

, there exist techniques which require projections data only in the All authors are with the Computer Science1 Spatially-Adaptive Reconstruction in Computed Tomography Based on Statistical Learning Joseph a direct reconstruction algorithm for Computed Tomography, based on a local fusion of a few preliminary

Zibulevsky, Michael

142

Limited Angle Tomography of Sparse Images from Noisy Data using TLS MUSIC Algorithm  

E-Print Network [OSTI]

1 Limited Angle Tomography of Sparse Images from Noisy Data using TLS MUSIC Algorithm Andrew E The limited angle tomography problem is to recon- struct an image x(y, z) from its projections p(t, ) p-shaped region. This has applications to med- ical imaging and non-destructive evaluation where projection data

Yagle, Andrew E.

143

BRAIN TUMOR VASCULAR NETWORK SEGMENTATION FROM MICRO-TOMOGRAPHY Xavier Descombes1  

E-Print Network [OSTI]

BRAIN TUMOR VASCULAR NETWORK SEGMENTATION FROM MICRO-TOMOGRAPHY Xavier Descombes1 , Franck for the systematic 3D analysis of supra- cellular structures such as micro-vascular networks [1, 2]. Since, France ABSTRACT Micro-tomography produces high resolution images of bio- logical structures

144

Investigating the stratigraphy of an alluvial aquifer using crosswell seismic traveltime tomography  

E-Print Network [OSTI]

can be used in situations where surface seismic reflection has failed e.g., Liberty et al., 1999Investigating the stratigraphy of an alluvial aquifer using crosswell seismic traveltime tomography In this study, we investigate the use of crosswell P-wave seismic tomography to obtain spatially extensive

Barrash, Warren

145

Computed tomography of the thorax: a status report  

SciTech Connect (OSTI)

Computed tomography (CT) of the thorax shows early promise of important diagnostic advances. We believe that CT often provides information superior to that provided by standard roentgenographic techniques, is capable of significantly influencing patient management, and in selected instances, offers unique information not available by other methods. Computed tomography permits the imaging of mediastinal structures not possible with conventional roentgenographic methods and can diagnose with certainty benign mediastinal conditions such as pericardial cysts and focal or diffuse accumulations of fat. It is ideal for detecting pleural abnormalities and for displaying underlying parenchymal disease in patients with complex pleuroparenchymal shadows on conventional films. Pulmonary metastases unseen on the plain chest film can be detected with greater sensitivity than by any other method. Future applications of CT include the staging of mediastinal lymph nodes in bronchogenic carcinoma, the differentiation of benign from malignant solitary pulmonary nodules, and the detection of diffuse diseases involving the lung parenchyma before they are visible on conventional roentgenograms. Additional clinical experience and careful studies will determine CTs final role as a diagnostic aid for disorders of the thorax.

Pugatch, R.D.; Faling, L.J.

1981-11-01T23:59:59.000Z

146

Quantifying the debonding of inclusions through tomography and computational homology.  

SciTech Connect (OSTI)

This report describes a Laboratory Directed Research and Development (LDRD) project to use of synchrotron-radiation computed tomography (SRCT) data to determine the conditions and mechanisms that lead to void nucleation in rolled alloys. The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL) has provided SRCT data of a few specimens of 7075-T7351 aluminum plate (widely used for aerospace applications) stretched to failure, loaded in directions perpendicular and parallel to the rolling direction. The resolution of SRCT data is 900nm, which allows elucidation of the mechanisms governing void growth and coalescence. This resolution is not fine enough, however, for nucleation. We propose the use statistics and image processing techniques to obtain sub-resolution scale information from these data, and thus determine where in the specimen and when during the loading program nucleation occurs and the mechanisms that lead to it. Quantitative analysis of the tomography data, however, leads to the conclusion that the reconstruction process compromises the information obtained from the scans. Alternate, more powerful reconstruction algorithms are needed to address this problem, but those fall beyond the scope of this project.

Lu, Wei-Yang; Johnson, George C. (University of California, Berkeley, Berkeley, CA); Mota, Alejandro; Foulk, James W., III; Jin, Huiqing

2010-09-01T23:59:59.000Z

147

LMFBR fuel bundle distortion characterization using neutron tomography and potting  

SciTech Connect (OSTI)

A standard liquid metal fast breeder reactor (LMFBR) subassembly used in the Experimental Breeder Reactor II (EBRII) was investigated for fuel bundle distortion by both nondestructive and destructive methods, and the results from both methods were compared. The nondestructive method employed neutron tomography to reconstruct the locations of fuel elements through the use of a maximum entropy reconstruction algorithm known as MENT. The destructive method consisted of ''potting'' (a technique that embeds and permanently fixes the fuel elements in a solid matrix) the subassembly and then cutting and polishing the individual sections. The comparison indicated that the tomography reconstruction provided good results in describing the bundle geometry and spacer-wire locations, with the overall resolution being on the order of a spacer-wire diameter. A dimensional consistency check indicated that the element and spacer-wire dimensions were accurately reproduced in the reconstruction. It was found that in situ fuel elements deform axially in a helical spiral and that the reconstruction was able to identify this helical distortion to within approximately half of a spacerwire diameter.

Betten, P.R.; Tow, D.M.

1984-05-01T23:59:59.000Z

148

Simultaneous CT and SPECT tomography using CZT detectors  

DOE Patents [OSTI]

A method for simultaneous transmission x-ray computed tomography (CT) and single photon emission tomography (SPECT) comprises the steps of: injecting a subject with a tracer compound tagged with a .gamma.-ray emitting nuclide; directing an x-ray source toward the subject; rotating the x-ray source around the subject; emitting x-rays during the rotating step; rotating a cadmium zinc telluride (CZT) two-sided detector on an opposite side of the subject from the source; simultaneously detecting the position and energy of each pulsed x-ray and each emitted .gamma.-ray captured by the CZT detector; recording data for each position and each energy of each the captured x-ray and .gamma.-ray; and, creating CT and SPECT images from the recorded data. The transmitted energy levels of the x-rays lower are biased lower than energy levels of the .gamma.-rays. The x-ray source is operated in a continuous mode. The method can be implemented at ambient temperatures.

Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Lubbock, TX); Simpson, Michael L. (Knoxville, TN); Britton, Jr., Charles L. (Alcoa, TN)

2002-01-01T23:59:59.000Z

149

Reconstruction from a flexible number of projections in cone-beam computed tomography via active shape models  

E-Print Network [OSTI]

Reconstruction from a flexible number of projections in cone-beam computed tomography via active, and limited view computed tomography. 1. INTRODUCTION In recent years, cone beam computed tomography (CBCT a limited set of projections. Evaluations were performed using simulations with Shepp-Logan phantoms

Corso, Jason J.

150

Iterative methods for dose reduction and image enhancement in tomography  

DOE Patents [OSTI]

A system and method for creating a three dimensional cross sectional image of an object by the reconstruction of its projections that have been iteratively refined through modification in object space and Fourier space is disclosed. The invention provides systems and methods for use with any tomographic imaging system that reconstructs an object from its projections. In one embodiment, the invention presents a method to eliminate interpolations present in conventional tomography. The method has been experimentally shown to provide higher resolution and improved image quality parameters over existing approaches. A primary benefit of the method is radiation dose reduction since the invention can produce an image of a desired quality with a fewer number projections than seen with conventional methods.

Miao, Jianwei; Fahimian, Benjamin Pooya

2012-09-18T23:59:59.000Z

151

Data fusion in neutron and X-ray computed tomography  

SciTech Connect (OSTI)

We present a fusion methodology between neutron and X-ray computed tomography (CT). On the one hand, the inspection by X-ray CT of a wide class of multimaterials in non-destructive testing applications suffers from limited information of object features. On the other hand, neutron imaging can provide complementary data in such a way that the combination of both data sets fully characterizes the object. In this contribution, a novel data fusion procedure, called Fusion Regularized Simultaneous Algebraic Reconstruction Technique, is developed where the X-ray reconstruction is modified to fulfill the available data from the imaging with neutrons. The experiments, which were obtained from an aluminum profile containing a steel screw, and attached carbon fiber plates demonstrate that the image quality in CT can be significantly improved when the proposed fusion method is used.

Schrapp, Michael J. [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 Munich (Germany); Physik Department E21, Technische Universität München, James-Franck-Strasse 1, 85747 Garching (Germany); Goldammer, Matthias [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 Munich (Germany); Schulz, Michael [Physik Department E21, Technische Universität München, James-Franck-Strasse 1, 85747 Garching (Germany); Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstrasse 1, 85747 Garching (Germany); Issani, Siraj; Bhamidipati, Suryanarayana [Siemens AG, Corporate Technology, Bangalore (India); Böni, Peter [Physik Department E21, Technische Universität München, James-Franck-Strasse 1, 85747 Garching (Germany)

2014-10-28T23:59:59.000Z

152

3D Jet Tomography of the Twisted Color Glass Condensate  

E-Print Network [OSTI]

Jet Tomography is proposed as a new test of Color Glass Condensate (CGC) initial conditions in non-central $A+A$ collisions. The $k_{T}$ factorized CGC formalism is used to calculate the rapidity twist in the reaction plane of both the bulk low $p_T 6$ GeV partons. Unlike conventional perturbative QCD, the initial high $p_{T}$ CGC gluons are shown to be twisted even further away from the beam axis than the the low $p_T$ bulk at high rapidities $|\\eta|>2$. Differential directed flow $v_{1}(p_{T}>6,|\\eta|>2)$ is proposed to test this novel high $p_T$ rapidity twist predicted by the CGC model.

A. Adil; M. Gyulassy; T. Hirano

2005-09-23T23:59:59.000Z

153

Electrical resistance tomography from measurements inside a steel cased borehole  

DOE Patents [OSTI]

Electrical resistance tomography (ERT) produced from measurements taken inside a steel cased borehole. A tomographic inversion of electrical resistance measurements made within a steel casing was then made for the purpose of imaging the electrical resistivity distribution in the formation remotely from the borehole. The ERT method involves combining electrical resistance measurements made inside a steel casing of a borehole to determine the electrical resistivity in the formation adjacent to the borehole; and the inversion of electrical resistance measurements made from a borehole not cased with an electrically conducting casing to determine the electrical resistivity distribution remotely from a borehole. It has been demonstrated that by using these combined techniques, highly accurate current injection and voltage measurements, made at appropriate points within the casing, can be tomographically inverted to yield useful information outside the borehole casing.

Daily, William D. (Livermore, CA); Schenkel, Clifford (Walnut Creek, CA); Ramirez, Abelardo L. (Pleasanton, CA)

2000-01-01T23:59:59.000Z

154

Temporoparietal cortex in aphasia. Evidence from positron emission tomography  

SciTech Connect (OSTI)

Forty-four aphasic patients were examined with (F18)-fluorodeoxyglucose positron emission tomography in a resting state to determine whether consistent glucose metabolic abnormalities were present. Ninety-seven percent of subjects showed metabolic abnormalities in the angular gyrus, 89% in the supramarginal gyrus, and 87% in the lateral and transverse superior temporal gyrus. Pearson product moment correlations were calculated between regional metabolic measures and performance on the Western Aphasia Battery. No significant correlations were found between the Western Aphasia Battery scores and right hemisphere metabolic measures. Most left hemisphere regions correlated with more than one score from the Western Aphasia Battery. Temporal but not frontal regions had significant correlations to the comprehension score. The left temporoparietal region was consistently affected in these subjects, suggesting that common features in the aphasias were caused by left temporoparietal dysfunction, while behavioral differences resulted from (1) the extent of temporoparietal changes, and (2) dysfunction elsewhere in the brain, particularly the left frontal and subcortical areas.

Metter, E.J.; Hanson, W.R.; Jackson, C.A.; Kempler, D.; van Lancker, D.; Mazziotta, J.C.; Phelps, M.E. (National Institute of Aging, Baltimore, MD (USA))

1990-11-01T23:59:59.000Z

155

Thermal stability of curved ray tomography for corrosion monitoring  

SciTech Connect (OSTI)

Guided wave tomography is being developed as an effective tool for continuous monitoring of corrosion and erosion depth in pipelines. A pair of transmit- and receive-ring arrays of ultrasonic transducers encircles the pipe and delimits the section to be monitored. In curved ray tomography (CRT), the depth profile is estimated from the time delay matrix, ??, whose ij-th entry is the phase traveltime difference between the current and baseline signals measured between transducers i and j of the transmit and receive-ring arrays, respectively. Under perfectly stable experimental conditions, the non-zero entries of ?? are only due to the occurrence of damage and provide a reliable input to CRT. However, during field operation, ?? can develop non-zero entries due to a number of environmental changes ranging from temperature variations to degradation of transducer-pipe coupling and transducer intrinsic performance. Here, we demonstrate that these sources of instability can be eliminated by exploiting the spatial diversity of array measurements in conjunction with EMAT transducer technology which is intrinsically stable owing to its non-contact nature. The study is based on a full-scale experiment performed on a schedule 40, 8’ diameter, 3 m length steel pipe, monitored with two EMAT ring arrays. It is shown that for an irregularly shaped defect the proposed method yields maximum depth estimations that are as accurate as single point ultrasonic thickness gaging measurements and over a wide temperature range up to 175°C. The results indicate that advanced inversion schemes in combination with EMAT transduction offer great potential for continuously monitoring the progression of corrosion or erosion damage in the oil and gas industry.

Willey, C. L. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, OH 45221 (United States); Simonetti, F.; Nagy, P. B. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, OH 45221,USA and Cincinnati NDE, Cincinnati, OH 45244 (United States); Instanes, G. [ClampOn AS, 5162 Laksevaag, Bergen, Norway and Cincinnati NDE, Cincinnati, OH 45244 (United States)

2014-02-18T23:59:59.000Z

156

Reconstruction algorithm for limited-angle diffraction tomography for microwave NDE  

SciTech Connect (OSTI)

Microwave tomography is becoming a popular imaging modality in nondestructive evaluation and medicine. A commonly encountered challenge in tomography in general is that in many practical situations a full 360° angular access is not possible and with limited access, the quality of reconstructed image is compromised. This paper presents an approach for reconstruction with limited angular access in diffraction tomography. The algorithm takes advantage of redundancies in image Fourier space data obtained from diffracted field measurements and couples it to an error minimization technique using a constrained total variation (CTV) minimization. Initial results from simulated data have been presented here to validate the approach.

Paladhi, P. Roy; Klaser, J.; Tayebi, A.; Udpa, L.; Udpa, S. [Non-destructive Evaluation Lab, Dept. of Electrical and Computer Engineering, College of Engineering, Michigan State University, Lansing, MI 48824-1226 (United States)

2014-02-18T23:59:59.000Z

157

A metallography and x-ray tomography study of spall damage in ultrapure Al  

SciTech Connect (OSTI)

We characterize spall damage in shock-recovered ultrapure Al with metallography and x-ray tomography. The measured damage profiles in ultrapure Al induced by planar impact at different shock strengths, can be described with a Gaussian function, and showed dependence on shock strengths. Optical metallography is reasonably accurate for damage profile measurements, and agrees within 10–25% with x-ray tomography. Full tomography analysis showed that void size distributions followed a power law with an exponent of ? = 1.5 ± 2.0, which is likely due to void nucleation and growth, and the exponent is considerably smaller than the predictions from percolation models.

Qi, M. L. [School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); HPSynC@Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bie, B. X. [School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); The Peac Institute of Multiscale Sciences and Sichuan University, Chengdu, Sichuan 610207 (China); Zhao, F. P.; Fan, D.; Luo, S. N., E-mail: sluo@pims.ac.cn [The Peac Institute of Multiscale Sciences and Sichuan University, Chengdu, Sichuan 610207 (China); Hu, C. M. [HPSynC@Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); National Key Laboratory of Shock Wave and Detonation Physics, Chinese Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Ran, X. X. [School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Xiao, X. H. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Yang, W. G., E-mail: wenge@aps.anl.gov [HPSynC@Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Li, P. [National Key Laboratory of Shock Wave and Detonation Physics, Chinese Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)

2014-07-15T23:59:59.000Z

158

Computed tomography in congenital hip dislocation. The role of acetabular anteversion  

SciTech Connect (OSTI)

Computed tomography usually can provide accurate documentation of the adequacy of a reduction in congenital dislocation of the hip. It should supplement other radiographic examinations when the status of a reduction is in question because the patient is wearing a plaster cast. The computed tomography scan provides a clear image of the reduction in the transverse plane, so that anterior or posterior subluxation of the femoral head can be easily detected. In addition it allows direct measurement of acetabular anteversion which previously had not been possible with non-invasive studies in the living patient. Radiation exposure is less than that for conventional tomography. We used computed tomography in five patients with congenital dislocation of the hip and our study provided new evidence concerning the role of acetabular anteversion in this condition. Acetabular anteversion was increased on the dislocated side in each patient, and returned to normal as treatment progressed.

Browning, W.H.; Rosenkrantz, H.; Tarquinio, T.

1982-01-01T23:59:59.000Z

159

Imaging the Soultz Enhanced Geothermal Reservoir using double-difference tomography and microseismic data  

E-Print Network [OSTI]

We applied the double-difference tomography method to image the P and S-wave velocity structure of the European Hot Dry Rock geothermal reservoir (also known as the Soultz Enhanced Geothermal System) at Soultz-sous-Forets, ...

Piñeros Concha, Diego Alvaro

2010-01-01T23:59:59.000Z

160

Endoscopic optical coherence tomography for clinical studies in the gastrointestinal tract  

E-Print Network [OSTI]

Optical coherence tomography (OCT) performs micrometer-scale, cross-sectional and three dimensional imaging by measuring the echo time delay of backscattered light. OCT imaging is performed using low-coherence interferometry. ...

Tsai, Tsung-Han, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Applications of Fourier Domain Mode Locked lasers for optical coherence tomography imaging  

E-Print Network [OSTI]

Optical coherence tomography (OCT) is a micrometer-resolution imaging technique that produces cross-sectional images of sample microstructure by measuring the amplitude and echo time delay of backscattered light. OCT imaging ...

Adler, Desmond Christopher, 1978-

2009-01-01T23:59:59.000Z

162

High-resolution three-dimensional optical coherence tomography imaging of kidney microanatomy ex vivo  

E-Print Network [OSTI]

Optical coherence tomography (OCT) is an emerging medical imaging technology that enables high-resolution, noninvasive, cross-sectional imaging of microstructure in biological tissues in situ and in real time. When combined ...

Chen, Yu

163

Method for Quantitative Study of Airway Functional Microanatomy Using Micro-Optical Coherence Tomography  

E-Print Network [OSTI]

We demonstrate the use of a high resolution form of optical coherence tomography, termed micro-OCT (?OCT), for investigating the functional microanatomy of airway epithelia. ?OCT captures several key parameters governing ...

Diephuis, Bradford J.

164

P- and S- wave tomography of the crust and uppermost mantle in China and surrounding areas  

E-Print Network [OSTI]

This thesis involves inverting the seismic structure of the crust and uppermost mantle in China from the P- and S-wave travel-time tomography. The main contributions of this research are: 1) introducing the adaptive moving ...

Sun, Youshun, 1970-

2005-01-01T23:59:59.000Z

165

One-step continuous synthesis of biocompatible gold nanorods for optical coherence tomography  

E-Print Network [OSTI]

We present a novel one-step flow process to synthesize biocompatible gold nanorods with tunable absorption and biocompatible surface ligands. Photothermal optical coherence tomography (OCT) of human breast tissue is ...

Sebastián, Víctor

166

Pulmonary Hypertension and Computed Tomography Measurement of Small Pulmonary Vessels in  

E-Print Network [OSTI]

Pulmonary Hypertension and Computed Tomography Measurement of Small Pulmonary Vessels in Severe alteration of small pulmonary vessels is one of the characteristic features of pulmonary hypertension in chronic obstruc- tive pulmonary disease. The in vivo relationship between pulmonary hypertension

167

Review paper Seismic interferometry and ambient noise tomography in the British Isles  

E-Print Network [OSTI]

Review paper Seismic interferometry and ambient noise tomography in the British Isles Heather. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 2. Theory and method of seismic interferometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 4.2. Seismic interferometry across the Scottish Highlands

168

Atherosclerotic tissue characterization in vivo by optical coherence tomography attenuation imaging  

E-Print Network [OSTI]

Optical coherence tomography (OCT) is rapidly becoming the method of choice for assessing arterial wall pathology in vivo. Atherosclerotic plaques can be diagnosed with high accuracy, including measurement of the thickness ...

Tearney, Guillermo J.

169

E-Print Network 3.0 - axial tomography suggestive Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

One aspect of the tomography assessment problem is to identify areas where the data suggest... into New Axial Volcano Magma Chamber Model, 100102-093005; 163,658; 2...

170

Diffraction and coherence in breast ultrasound tomography: a study with a toroidal array  

SciTech Connect (OSTI)

Ultrasound is commonly used as an adjunct to mammography for diagnostic evaluation of suspicions arising from breast cancer screening. As an alternative to conventional sonography that uses hand-held transducers, toroidal array probes that encircle the breast immersed in a water bath have been investigated for ultrasound tomography. In this paper, two sets of experiments performed with a prototype ultrasound scanner on a phantom and a human breast in vivo are used to investigate the effects of diffraction and coherence in ultrasound tomography. Reconstructions obtained with transmission diffraction tomography (TDT) are compared with conventional reflection imaging and computerized ultrasound tomography showing a substantial improvement. The in vivo tests demonstrate that TDT can image the complex boundary of a cancer mass and suggest that it can reveal the anatomy of milk ducts and Cooper's ligaments.

Huang, Lianjie [Los Alamos National Laboratory; Simonetti, Francesco [IMPERIAL COLL.; Duric, Neb [KCI; Littrup, Peter [KCI

2008-01-01T23:59:59.000Z

171

Optical coherence tomography based on intensity correlations of quasi-thermal light  

E-Print Network [OSTI]

We show theoretically that the longitudinal resolution of conventional optical coherence tomography can be improved by a factor of radic2 when a two-photon (as opposed to a single-photon) sensitive detector is used, and ...

Zerom, Petros

172

Progress toward scalable tomography of quantum maps using twirling-based methods and information hierarchies  

E-Print Network [OSTI]

We present in a unified manner the existing methods for scalable partial quantum process tomography. We focus on two main approaches: the one presented in Bendersky et al. [Phys. Rev. Lett. 100, 190403 (2008)] and the ones ...

Lopez, Cecilia Carolina

173

Digital signal processing techniques for optical coherence tomography : OCT and OCT image enhancement  

E-Print Network [OSTI]

Digital signal processing (DSP) techniques were developed to improve the flexibility, functionality, and image quality of ultrahigh resolution optical coherence tomography (OCT) systems. To reduce the dependence of OCT ...

Adler, Desmond Christopher, 1978-

2004-01-01T23:59:59.000Z

174

A microwave tomography system using a tunable mirror for beam steering  

SciTech Connect (OSTI)

Microwave tomography is a fast-growing technique in the fields of NDE and medical industry. This paper presents a new microwave tomography system which reduces the complexities of conventional microwave imaging systems by utilizing a reconfigurable mirror, a tunable reflectarray antenna. In order to build a tunable reflectarray with beam steering capabilities, the unit cell characteristics should dynamically alter. Modelling and experimental results of a single unit cell are presented in this work.

Tayebi, A. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physic (United States); Tang, J. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Paladhi, P. Roy; Udpa, L.; Udpa, S. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

2014-02-18T23:59:59.000Z

175

Compressed sensing quantum process tomography for superconducting quantum gates  

E-Print Network [OSTI]

We apply the method of compressed sensing (CS) quantum process tomography (QPT) to characterize quantum gates based on superconducting Xmon and phase qubits. Using experimental data for a two-qubit controlled-Z gate, we obtain an estimate for the process matrix $\\chi$ with reasonably high fidelity compared to full QPT, but using a significantly reduced set of initial states and measurement configurations. We show that the CS method still works when the amount of used data is so small that the standard QPT would have an underdetermined system of equations. We also apply the CS method to the analysis of the three-qubit Toffoli gate with numerically added noise, and similarly show that the method works well for a substantially reduced set of data. For the CS calculations we use two different bases in which the process matrix $\\chi$ is approximately sparse, and show that the resulting estimates of the process matrices match each ther with reasonably high fidelity. For both two-qubit and three-qubit gates, we characterize the quantum process by not only its process matrix and fidelity, but also by the corresponding standard deviation, defined via variation of the state fidelity for different initial states.

Andrey V. Rodionov; Andrzej Veitia; R. Barends; J. Kelly; Daniel Sank; J. Wenner; John M. Martinis; Robert L. Kosut; Alexander N. Korotkov

2014-07-03T23:59:59.000Z

176

Measurement strategy for rectangular electrical capacitance tomography sensor  

SciTech Connect (OSTI)

To investigate the influence of the measurement strategy for the rectangular electrical capacitance tomography (ECT) sensor, a Finite Element Method (FEM) is utilized to create the model for simulation. The simulation was carried out using COMSOL Multiphysics(trade mark, serif) and Matlab(trade mark, serif). The length-width ratio of the rectangular sensing area is 5. Twelve electrodes are evenly arranged surrounding the pipe. The covering ratio of the electrodes is 90%. The capacitances between different electrode pairs are calculated for a bar distribution. The air of the relative permittivity 1.0 and the material of the permittivity 3.0 are used for the calibration. The relative permittivity of the second phase is 3.0. The noise free and noise data are used for the image reconstruction using the Linear Back Projection (LBP). The measurement strategies with 1-, 2- and 4- electrode excitation are compared using the correlation coefficient. Preliminary results show that the measurement strategy with 2-electrode excitation outperforms other measurement strategies with 1- or 4-electrode excitation.

Ye, Jiamin; Ge, Ruihuan; Qiu, Guizhi; Wang, Haigang [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing, 100190 (China)

2014-04-11T23:59:59.000Z

177

Ultrasonic multi-skip tomography for pipe inspection  

SciTech Connect (OSTI)

The inspection of wall loss corrosion is difficult at pipe supports due to limited accessibility. The recently developed ultrasonic Multi-Skip screening technique is suitable for this problem. The method employs ultrasonic transducers in a pitch-catch geometry positioned on opposite sides of the pipe support. Shear waves are transmitted in the axial direction within the pipe wall, reflecting multiple times between the inner and outer surfaces before reaching the receivers. Along this path, the signals accumulate information on the integral wall thickness (e.g., via variations in travel time). The method is very sensitive in detecting the presence of wall loss, but it is difficult to quantify both the extent and depth of the loss. Multi-skip tomography has been developed to reconstruct the wall thickness profile along the axial direction of the pipe. The method uses model-based full wave field inversion; this consists of a forward model for predicting the measured wave field and an iterative process that compares the predicted and measured wave fields and minimizes the differences with respect to the model parameters (i.e., the wall thickness profile). Experimental results are very encouraging. Various defects (slot and flat bottom hole) are reconstructed using the tomographic inversion. The general shape and width are well recovered. The current sizing accuracy is in the order of 1 mm.

Volker, Arno; Zon, Tim van [TNO, Stieltjesweg 1, P.O. Box 155 2600 AD Delft (Netherlands)

2014-02-18T23:59:59.000Z

178

Quantum process tomography of unitary and near-unitary maps  

E-Print Network [OSTI]

We study quantum process tomography given the prior information that the map is a unitary or close to a unitary process. We show that a unitary map on a $d$-level system is completely characterized by a minimal set of $d^2{+}d$ elements associated with a collection of POVMs, in contrast to the $d^4{-}d^2$ elements required for a general completely positive trace-preserving map. To achieve this lower bound, one must probe the map with a particular set of $d$ pure states. We further compare the performance of different compressed sensing algorithms used to reconstruct a near-unitary process from such data. We find that when we have accurate prior information, an appropriate compressed sensing method reduces the required data needed for high-fidelity estimation, and different estimators applied to the same data are sensitive to different types of noise. Compressed sensing techniques can therefore be used both as indicators of error models and to validate the use of the prior assumptions.

Charles H. Baldwin; Amir Kalev; Ivan H. Deutsch

2014-04-22T23:59:59.000Z

179

Artifact reduction in industrial computed tomography via data fusion  

SciTech Connect (OSTI)

As the most stressed part of a gas turbine the first row of turbine blades is not only a challenge for the materials used. Also the testing of these parts have to meet the highest standards. Computed tomography (CT) as the technique which could reveal the most details also provides the biggest challenges [1]: A full penetration of large sized turbine blades is often only possible at high X-ray voltages causing disproportional high costs. A reduction of the X-ray voltage is able to reduce these arising costs but yields non penetration artifacts in the reconstructed CT image. In most instances, these artifacts manifests itself as blurred and smeared regions at concave edges due to a reduced signal to noise ratio. In order to complement the missing information and to increase the overall image quality of our reconstruction, we use further imaging modalities such as a 3-D Scanner and ultrasonic imaging. A 3-D scanner is easy and cost effective to implement and is able to acquire all relevant data simultaneously with the CT projections. If, however, the interior structure is of supplemental interest, an ultrasonic imaging method is additionally used. We consider this data as a priori knowledge to employ them in an iterative reconstruction. To do so, standard iterative reconstruction methods are modified to incorporate the a priori data in a regularization approach in combination with minimizing the total variation of our image. Applying this procedure on turbine blades, we are able to reduce the apparent artifacts almost completely.

Schrapp, Michael; Goldammer, Matthias; Stephan, Jürgen [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 Munich (Germany)

2014-02-18T23:59:59.000Z

180

Digital Radiography and Computed Tomography (DRCT) Product Improvement Plan (PIP)  

SciTech Connect (OSTI)

The Idaho National Laboratory (INL) has been developing and deploying x-ray inspection systems for chemical weapons containers for the past 12 years under the direction of the Project Manager for Non-Stockpile Chemical Materiel (PMNSCM). In FY-10 funding was provided to advance the capabilities of these systems through the DRCT (Digital Radiography and Computed Tomography) Product Improvement Plan (PIP), funded by the PMNSCM. The DRCT PIP identified three research tasks; end user study, detector evaluation and DRCT/PINS integration. Work commenced in February, 2010. Due to the late start and the schedule for field inspection of munitions at various sites, it was not possible to spend sufficient field time with operators to develop a complete end user study. We were able to interact with several operators, principally Mr. Mike Rowan who provided substantial useful input through several discussions and development of a set of field notes from the Pueblo, CO field mission. We will be pursuing ongoing interactions with field personnel as opportunities arise in FY-11.

Tim Roney; Bob Pink; Karen Wendt; Robert Seifert; Mike Smith

2010-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Using electrical resistance tomography to map subsurface temperatures  

DOE Patents [OSTI]

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations. 1 fig.

Ramirez, A.L.; Chesnut, D.A.; Daily, W.D.

1994-09-13T23:59:59.000Z

182

Electrical resistance tomography using steel cased boreholes as electrodes  

DOE Patents [OSTI]

An electrical resistance tomography method is described which uses steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constrain the models. 2 figs.

Daily, W.D.; Ramirez, A.L.

1999-06-22T23:59:59.000Z

183

Electrical resistance tomography using steel cased boreholes as electrodes  

DOE Patents [OSTI]

An electrical resistance tomography method using steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constain the models.

Daily, William D. (Livermore, CA); Ramirez, Abelardo L. (Pleasanton, CA)

1999-01-01T23:59:59.000Z

184

Using electrical resistance tomography to map subsurface temperatures  

DOE Patents [OSTI]

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations.

Ramirez, Abelardo L. (Pleasanton, CA); Chesnut, Dwayne A. (San Francisco, CA); Daily, William D. (Livermore, CA)

1994-01-01T23:59:59.000Z

185

Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs  

SciTech Connect (OSTI)

Purpose: Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. Methods and Materials: We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. Results: PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). Conclusions: For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes, mediastinal lymph nodes, and unsuspected sites of distant metastasis. This information is important in the design of radiotherapy treatment fields and, therefore, we recommend that PET/CT be a component of initial staging for IBC.

Walker, Gary V. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Niikura, Naoki [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan)] [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan); Yang Wei [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rohren, Eric [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Valero, Vicente [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Alvarez, Ricardo H. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lucci, Anthony [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A., E-mail: tbuchhol@mdanderson.org [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2012-08-01T23:59:59.000Z

186

X-ray Computed Tomography of coal: Final report  

SciTech Connect (OSTI)

X-ray Computed Tomography (CT) is a method of mapping with x-rays the internal structures of coal. The technique normally produces 2-D images of the internal structures of an object. These images can be recast to create pseudo 3-D representations. CT of coal has been explored for a variety of different applications to coal and coal processing technology. In a comparison of CT data with conventional coal analyses and petrography, CT was found to offer a good indication of the total ash content of the coal. The spatial distribution of the coal mineral matter as seen with CT has been suggested as an indicator of coal washability. Studies of gas flow through coal using xenon gas as a tracer have shown the extremely complicated nature of the modes of penetration of gas through coal, with significant differences in the rates at which the gas can pass along and across the bedding planes of coal. In a special furnace designed to allow CT images to be taken while the coal was being heated, the pyrolysis and gasification of coal have been studied. Gasification rates with steam and CO/sub 2/ for a range of coal ranks have been obtained, and the location of the gasification reactions within the piece of coal can be seen. Coal drying and the progress of the pyrolysis wave into coal have been examined when the coal was subjected to the kind of sudden temperature jump that it might experience in fixed bed gasifier applications. CT has also been used to examine stable flow structures within model fluidized beds and the accessibility of lump coal to microbial desulfurization. 53 refs., 242 figs., 26 tabs.

Maylotte, D.H.; Spiro, C.L.; Kosky, P.G.; Lamby, E.J.

1986-12-01T23:59:59.000Z

187

Prior-based artifact correction (PBAC) in computed tomography  

SciTech Connect (OSTI)

Purpose: Image quality in computed tomography (CT) often suffers from artifacts which may reduce the diagnostic value of the image. In many cases, these artifacts result from missing or corrupt regions in the projection data, e.g., in the case of metal, truncation, and limited angle artifacts. The authors propose a generalized correction method for different kinds of artifacts resulting from missing or corrupt data by making use of available prior knowledge to perform data completion. Methods: The proposed prior-based artifact correction (PBAC) method requires prior knowledge in form of a planning CT of the same patient or in form of a CT scan of a different patient showing the same body region. In both cases, the prior image is registered to the patient image using a deformable transformation. The registered prior is forward projected and data completion of the patient projections is performed using smooth sinogram inpainting. The obtained projection data are used to reconstruct the corrected image. Results: The authors investigate metal and truncation artifacts in patient data sets acquired with a clinical CT and limited angle artifacts in an anthropomorphic head phantom data set acquired with a gantry-based flat detector CT device. In all cases, the corrected images obtained by PBAC are nearly artifact-free. Compared to conventional correction methods, PBAC achieves better artifact suppression while preserving the patient-specific anatomy at the same time. Further, the authors show that prominent anatomical details in the prior image seem to have only minor impact on the correction result. Conclusions: The results show that PBAC has the potential to effectively correct for metal, truncation, and limited angle artifacts if adequate prior data are available. Since the proposed method makes use of a generalized algorithm, PBAC may also be applicable to other artifacts resulting from missing or corrupt data.

Heußer, Thorsten, E-mail: thorsten.heusser@dkfz-heidelberg.de; Brehm, Marcus [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Ritschl, Ludwig [Ziehm Imaging GmbH, Donaustraße 31, 90451 Nürnberg (Germany)] [Ziehm Imaging GmbH, Donaustraße 31, 90451 Nürnberg (Germany); Sawall, Stefan; Kachelrieß, Marc [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, Friedrich–Alexander–University (FAU) of Erlangen–Nürnberg, Henkestraße 91, 91052 Erlangen (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, Friedrich–Alexander–University (FAU) of Erlangen–Nürnberg, Henkestraße 91, 91052 Erlangen (Germany)

2014-02-15T23:59:59.000Z

188

Application of stochastic Galerkin FEM to the complete electrode model of electrical impedance tomography  

SciTech Connect (OSTI)

The aim of electrical impedance tomography is to determine the internal conductivity distribution of some physical body from boundary measurements of current and voltage. The most accurate forward model for impedance tomography is the complete electrode model, which consists of the conductivity equation coupled with boundary conditions that take into account the electrode shapes and the contact resistances at the corresponding interfaces. If the reconstruction task of impedance tomography is recast as a Bayesian inference problem, it is essential to be able to solve the complete electrode model forward problem with the conductivity and the contact resistances treated as a random field and random variables, respectively. In this work, we apply a stochastic Galerkin finite element method to the ensuing elliptic stochastic boundary value problem and compare the results with Monte Carlo simulations.

Leinonen, Matti, E-mail: matti.leinonen@aalto.fi; Hakula, Harri, E-mail: harri.hakula@aalto.fi; Hyvönen, Nuutti, E-mail: nuutti.hyvonen@aalto.fi

2014-07-15T23:59:59.000Z

189

FIB–SEM tomography of 4th generation PWA 1497 superalloy  

SciTech Connect (OSTI)

The effect of creep deformation on the microstructure of the PWA 1497 single crystal Ni-base superalloy developed for turbine blade applications was investigated. The aim of the present study was to characterize quantitatively a superalloy microstructure and subsequent development of rafted ?? precipitates in the PWA 1497 during creep deformation at 982 °C and 248 MPa up to rupture. The PWA1497 microstructure was characterized by scanning electron microscopy and FIB–SEM electron tomography. The 3D reconstruction of the PWA1497 microstructure is presented and discussed. - Highlights: • The microstructure of PWA1497 superalloy was examined using FIB–SEM tomography. • In case of modern single crystal superalloys, measurements of A{sub A} are adequate for V{sub V}. • During creep the ? channel width increases from 65 to 193 nm for ruptured specimen. • Tomography is a useful technique for quantitative studies of material microstructure.

Zi?tara, Maciej, E-mail: zietara@agh.edu.pl; Kruk, Adam, E-mail: kruczek@agh.edu.pl; Gruszczy?ski, Adam, E-mail: gruszcz@agh.edu.pl; Czyrska-Filemonowicz, Aleksandra, E-mail: czyrska@agh.edu.pl

2014-01-15T23:59:59.000Z

190

VSoE RIF Report: Micro-Tomography P.I.: Young H. Cho, Research Assistant Professor, Dept of EE/Dept of CS  

E-Print Network [OSTI]

VSoE RIF Report: Micro-Tomography P.I.: Young H. Cho, Research Assistant Professor, Dept of EE to the expense of buoys, floats or robotic probes. By performing acoustic tomography between shore or buoy

Zhou, Chongwu

191

F Labeling of a Near-Infrared Fluorophore Enables Positron Emission Tomography and Optical Imaging of Sentinel Lymph Nodes  

E-Print Network [OSTI]

Fast 18 F Labeling of a Near-Infrared Fluorophore Enables Positron Emission Tomography and Optical- with a near-infrared fluorophore into a single molecule. Attachment to targeting ligands enables localization by positron emission tomography (PET) and near-infrared fluorescence (NIRF). Our first application

Tsien, Roger Y.

192

Cone-beam mammo-computed tomography from data along two tilting arcs Hengyong Yu,b  

E-Print Network [OSTI]

Cone-beam mammo-computed tomography from data along two tilting arcs Kai Zeng,a Hengyong Yu . To address this problem, x-ray tomosynthesis and cone-beam computed tomography CT are two compelling from a limited num- ber of projections.4 Since its introduction in 1972, the area of tomosynthesis has

Virginia Tech

193

An overview of fast convergent ordered-subsets reconstruction methods for emission tomography based on the incremental EM  

E-Print Network [OSTI]

. Introduction In emission tomography, the reconstruction of vast quantities of noisy, low-count data in prac [4]. Statistical reconstruction is useful in emission computed tomography due to its ability to ac by using only a subset of the projection data per sub-iteration. The OSEM algorithm is fast, parallelizable

Rangarajan, Anand

194

ECG-GATED C-ARM COMPUTED TOMOGRAPHY USING L1 REGULARIZATION Cyril Mory 1,3  

E-Print Network [OSTI]

ECG-GATED C-ARM COMPUTED TOMOGRAPHY USING L1 REGULARIZATION Cyril Mory 1,3 , Bo Zhang 3 , Vincent of the algorithm used for the minimization. Index Terms -- C-Arm, computed tomography, ECG- gating, augmented arises from the synchronization with the patient's electrocardiogram (ECG), which is necessary to avoid

Paris-Sud XI, Université de

195

Multi-Resolution Seismic Tomography Based on Recursive Tessellation Hierarchy  

SciTech Connect (OSTI)

A 3-D global tomographic model that reconstructs velocity structure at multiple scales and incorporates laterally variable seismic discontinuities is currently being developed. The model parameterization is node-based where nodes are placed along vertices defined by triangular tessellations of a spheroidal surface. The triangular tessellation framework is hierarchical. Starting with a tetrahexahedron representing the whole globe (1st level of the hierarchy, 24 faces), they divide each triangle of the tessellation into daughter triangles. The collection of all daughter triangles comprises the 2nd level of the tessellation hierarchy and further recursion produces an arbitrary number of tessellation levels and arbitrarily fine node-spacing. They have developed an inversion procedure that takes advantage of the recursive properties of the tessellation hierarchies by progressively solving for shorter wavelength heterogeneities. In this procedure, we first perform the tomographic inversion using a tessellation level with coarse node spacing. They find that a coarse node spacing of approximately 8{sup o} is adequate to capture bulk regional properties. They then conduct the tomographic inversion on a 4{sup o} tessellation level using the residuals and inversion results from the 8{sup o} run. In practice they find that the progressive tomography approach is robust, providing an intrinsic regularization for inversion stability and avoids the issue of predefining resolution levels. Further, determining average regional properties with coarser tessellation levels enables long-wavelength heterogeneities to account for sparsely sampled regions (or regions of the mantle where longer wavelength patterns of heterogeneity suffice) while allowing shorter length-scale heterogeneities to emerge where necessary. They demonstrate the inversion approach with a set of synthetic test cases that mimic the complex nature of data arrangements (mixed-determined inversion) common to most tomographic problems. They also apply the progressive inversion approach with Pn waves traveling within the Middle East region and compare the results to simple tomographic inversions. As expected from synthetic testing, the progressive approach results in detailed structure where there is high data density and broader regional anomalies where seismic information is sparse. The ultimate goal is to use these methods to produce a seamless, multi-resolution global tomographic model with local model resolution determined by the constraints afforded by available data. They envisage this new technique as the general approach to be employed for future multi-resolution model development with complex arrangements of regional and teleseismic information.

Simmons, N A; Myers, S C; Ramirez, A

2009-07-01T23:59:59.000Z

196

Improved proton computed tomography by dual modality image reconstruction  

SciTech Connect (OSTI)

Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations for particle therapy. However, the finite range of about 33 cm of water of most commercial proton therapy systems limits the sites that can be scanned from a full 360° rotation. In this paper the authors propose a method to overcome the problem using a dual modality reconstruction (DMR) combining the proton data with a cone-beam x-ray prior. Methods: A Catphan 600 phantom was scanned using a cone beam x-ray CT scanner. A digital replica of the phantom was created in the Monte Carlo code Geant4 and a 360° proton CT scan was simulated, storing the entrance and exit position and momentum vector of every proton. Proton CT images were reconstructed using a varying number of angles from the scan. The proton CT images were reconstructed using a constrained nonlinear conjugate gradient algorithm, minimizing total variation and the x-ray CT prior while remaining consistent with the proton projection data. The proton histories were reconstructed along curved cubic-spline paths. Results: The spatial resolution of the cone beam CT prior was retained for the fully sampled case and the 90° interval case, with the MTF = 0.5 (modulation transfer function) ranging from 5.22 to 5.65?linepairs/cm. In the 45° interval case, the MTF = 0.5 dropped to 3.91?linepairs/cm For the fully sampled DMR, the maximal root mean square (RMS) error was 0.006 in units of relative stopping power. For the limited angle cases the maximal RMS error was 0.18, an almost five-fold improvement over the cone beam CT estimate. Conclusions: Dual modality reconstruction yields the high spatial resolution of cone beam x-ray CT while maintaining the improved stopping power estimation of proton CT. In the case of limited angles, the use of prior image proton CT greatly improves the resolution and stopping power estimate, but does not fully achieve the quality of a 360° proton CT scan.

Hansen, David C., E-mail: dch@ki.au.dk; Bassler, Niels [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark)] [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark); Petersen, Jørgen Breede Baltzer [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark)] [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark); Sørensen, Thomas Sangild [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)] [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)

2014-03-15T23:59:59.000Z

197

Characterizing properties of fractured porous media using x-ray computed tomography  

E-Print Network [OSTI]

CHARACTERIZING PROPERTIES OF FRACTURED POROUS MEDIA USING X-RAY COMPUTED TOMOGRAPHY A Thesis by JAMES MUDRA IV Submitted to the O f f i c e of Graduate Studies of Texas A&M University- p a r t i a l f u l f i l l m e n t of the requirements f... or the degree of MASTER OF SCIENCE December 1990 Major Subject: Chemical Engineering CHARACTERIZING PROPERTIES OF FRACTURED POROUS MEDIA USING X-RAY COMPUTED TOMOGRAPHY A Thesis by JAMES MUDRA IV Approved as to s t y l e and content by: (Member) (Head...

Mudra, James

2012-06-07T23:59:59.000Z

198

A novel synthetic aperture technique for breast tomography with toroidal arrays  

SciTech Connect (OSTI)

Ultrasound is commonly used as an adjunct to mammography for diagnostic evaluation of suspicions arising from breast cancer screening. As an alternative to conventional sonography that uses hand-held transducers, toroidal array probes that encircle the breast immersed in a water bath have been investigated for ultrasound tomography. This paper introduces a new method for three-dimensional synthetic aperture diffraction tomography that maximizes the resolution in the scanning direction and provides quantitative reconstructions of the acoustic properties of the object. The method is validated by means of numerical simulations.

Huang, Lianjie [Los Alamos National Laboratory; Simonetti, Francesco [IMPERIAL COLLEGE

2009-01-01T23:59:59.000Z

199

Post-doc GIPSA-Lab / LGIT : Ocean Acoustic Tomography in shallow water and Signal Processing  

E-Print Network [OSTI]

Post-doc GIPSA-Lab / LGIT : Ocean Acoustic Tomography in shallow water and Signal Processing influence and pollution in coastal areas. Consequently, they need the precise knowledge of the spatial and to estimate the sur- face height is also very interesting as these problems have many applications (acoustic

van Tiggelen, Bart

200

Quantum process tomography of single photon quantum channels with controllable decoherence  

E-Print Network [OSTI]

We characterized unital quantum channels of single photon polarization qubits. The channels are composed of two birefringent crystals and wave-plates, where their decoherence properties are controlled. An experimental comparison between two different depolarizing configurations was performed using a quantum process tomography procedure. The results are with a high fidelity to the theoretical predictions.

A. Shaham; H. S. Eisenberg

2011-08-07T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada  

E-Print Network [OSTI]

Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada Roland Gritto, Valeri A in the proposed nuclear waste repository area at Yucca Mountain, Nevada. A 5-km-long source line and a 3-km-long receiver line were located on top of Yucca Mountain ridge and inside the Exploratory Study Facility (ESF

Korneev, Valeri A.

202

Transport-and diffusion-based optical tomography in small domains: a comparative study  

E-Print Network [OSTI]

reconstructions based on the radiative transport and diffusion equations in optical tomography for media of small that the propaga- tion of near-infrared light in tissues is best modeled by the radiative transport equation (RTE the transport equation by its diffusion approximation, which models the spa- tial density of photons

Bal, Guillaume

203

T. J. Brukilacchio, Ph.D. Thesis 2003 Review of Diffuse Optical Tomography  

E-Print Network [OSTI]

to the radiative transport equation. Analytical models have been developed for simple geometries Optical Tomography The diffusion approximation to the radiative transport equation is the most widely used extensively studied in atmospheric physics, and in neutron transport [1,2]. The radiative transfer equation

204

Three-dimensional optical tomography with the equation of radiative transfer  

E-Print Network [OSTI]

on a transport-backtransport method applied to the two-dimensional time-dependent equation of radiative transferThree-dimensional optical tomography with the equation of radiative transfer Gassan S. Abdoulaev reconstruction scheme that is based on the time-independent equation of radiative transfer (ERT) and allows

Hielscher, Andreas

205

Determination of cloud liquid water distribution using 3D cloud tomography  

E-Print Network [OSTI]

, but they provide a less direct measurement of cloud water content (since radar reflectivity depends strongly, the number of scanning angles, the radiometer characteristics (e.g., noise level, beam width), the physical accuracy. For a setup consisting of four microwave radiometers of typical noise level 0.3 K, the tomography

206

BOREHOLE RADAR ATTENUATION-DIFFERENCE TOMOGRAPHY DURING THE TRACER/TIME-LAPSE TEST AT THE BOISE  

E-Print Network [OSTI]

to those suggested by radar level run attenuation differences, shot-receiver attenuation difference be explained by the difference in support volumes for the radar and chemistry measurements, and alsoBOREHOLE RADAR ATTENUATION-DIFFERENCE TOMOGRAPHY DURING THE TRACER/TIME-LAPSE TEST AT THE BOISE

Barrash, Warren

207

Diffuse Optical Tomography of Cerebral Blood Flow, Oxygenation, and Metabolism in Rat During Focal Ischemia  

E-Print Network [OSTI]

of oxygen consumption (CMRO2). Temporary (60-minute) MCAO was performed on five rats. Ischemic changes--Cerebral metabolic rate of oxygen consumption. Diffuse optical tomography (DOT) of the brain is an attractive new complementary to those of magnetic resonance imaging (MRI) and positron emission tomog- raphy (PET), and holds

Yodh, Arjun G.

208

Nondestructive evaluation of Polymer Coating Structures on Pharmaceutical Pellets using Full Field Optical Coherence Tomography  

E-Print Network [OSTI]

Full field optical coherence tomography (FF-OCT) using a conventional LED light source and a CMOS camera has been developed for characterising coatings on small pellet samples. A set of en-face images covering an area of 700µm x 700µm were taken...

Li, C; Zeitler, J. A; Dong, Y; Shen, Y.-C

209

Using X-ray computed tomography in hydrology: systems, resolutions, and limitations  

E-Print Network [OSTI]

Using X-ray computed tomography in hydrology: systems, resolutions, and limitations D and Environmental Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA c Hydrology Ltd. All rights reserved. PII: S0022-1694(02)00157-9 Journal of Hydrology 267 (2002) 285­297 www

Wildenschild, Dorthe

210

Noninvasive Monitoring of Local Drug Release Using X-ray Computed Tomography: Optimization and  

E-Print Network [OSTI]

-performanceliquidchromatography(HPLC), high resolution mass spectrometry, or atomic absorption spectrometry (AAS). These procedures,3 Gamma-emission imaging, positron- emission tomography (PET), and magnetic reso- nance imaging (MRI of these methods are rela- tively low spatial resolution (5 and 10 mm for clinical gamma imaging and PET

Gao, Jinming

211

Geophys. J. Int. () , 1?? Cross-section electrical resistance tomography of La Soufri`ere of  

E-Print Network [OSTI]

to unconsolidated material saturated by hydrothermal fluids. Two of them are associated with partial flank collapses. Key words: Electrical properties ­ tomography ­ image processing ­ Volcanic hazards and risks 1 in the hydrothermal reservoirs and produces episodic chlorine spikes in the Carbet hot spring located on the north

Adler, Andy

212

Cross gender-age trabecular texture analysis in cone beam computed tomography  

E-Print Network [OSTI]

osteoporosis screening tools in the jaws. Keywords: cone-beam computed tomography, osteoporosis, radiology, osteoporosis afflicts 55% of Americans aged 50 and above.1 Early diagnosis of osteoporosis is very important to prevent more serious complications such as hip fracture. The current gold standard for osteoporosis

Ling, Haibin

213

Time-lapse electrical resistivity tomography applied to cave sustainability (Barbados) and groundwater exploration (Saint Lucia)  

E-Print Network [OSTI]

In this work we apply the method of two-dimensional time-lapse electrical resistivity tomography (2D time-lapse ERT) for two different problems. In the first problem, we monitor the structural stability of the roof of the ...

Agramakova, Yulia

2011-01-01T23:59:59.000Z

214

An Efficient Approach for Optical Radiative Transfer Tomography using the Spherical Harmonics Discrete Ordinates Method  

E-Print Network [OSTI]

This paper introduces a method to preform optical tomography, using 3D radiative transfer as the forward model. We use an iterative approach predicated on the Spherical Harmonics Discrete Ordinates Method (SHDOM) to solve the optimization problem in a scalable manner. We illustrate with an application in remote sensing of a cloudy atmosphere.

Levis, Aviad; Aides, Amit; Davis, Anthony B

2015-01-01T23:59:59.000Z

215

An Exact Modeling of Signal Statistics in Energy-integrating X-ray Computed Tomography  

E-Print Network [OSTI]

assumption was made that the number of x-ray quanta within an energy interval in the spectrum followsAn Exact Modeling of Signal Statistics in Energy-integrating X-ray Computed Tomography Yi Fan1 School of Medicine, Atlanta, GA 30322 ABSTRACT Energy-integrating detection of x-ray sources is widely

216

XEDS STEM Tomography For 3D Chemical Characterization Of Nanoscale Particles  

SciTech Connect (OSTI)

We present a tomography technique which couples scanning transmission electron microscopy (STEM) and X-ray energy dispersive spectrometry (XEDS) to resolve 3D distribution of elements in nanoscale materials. STEM imaging when combined with a symmetrically arranged XEDS detector design around the specimen overcomes many of the obstacles in 3D spectroscopic tomography of nanoscale materials and successfully elucidate the 3D chemical information in a large field of view of the TEM sample. We employed this technique to investigate 3D distribution of Nickel (Ni), Manganese (Mn) and Oxygen (O) in Li(NiMn)O2 battery cathode material. For this purpose, 2D elemental maps were acquired for a range of tilt angles and reconstructed to obtain 3D elemental distribution in an isolated Li(NiMnO2) nanoparticle. The results highlight the strength of this technique in 3D chemical analysis of nanoscale materials by successfully resolving Ni, Mn and O elemental distributions in 3D and discovering the new phenomenon of Ni surface segregation in this material. Furthermore, the comparison of simultaneously acquired HAADF STEM and XEDS STEM tomography results show that XEDS STEM tomography provides additional 3D chemical information of the material especially when there is low atomic number (Z) contrast in the material of interest.

Genc, Arda; Kovarik, Libor; Gu, Meng; Cheng, Huikai; Plachinda, Pavel; Pullan, Lee; Freitag, Bert; Wang, Chong M.

2013-08-01T23:59:59.000Z

217

Radiation dose reduction and image enhancement in biological imaging through equally-sloped tomography  

E-Print Network [OSTI]

Iterative reconstruction algorithm Radiation dose reduction Image enhancement Computed tomography a b s t r-dose data acquisi- tion schemes have made it possible to record multiple projections quickly without-energy electrons (Henderson, 1995), which limits the number of projections that can be acquired. Furthermore

Miao, Jianwei "John"

218

Image Reconstruction for Positron Emission Tomography Using Fuzzy Nonlinear Anisotropic Diffusion Penalty  

E-Print Network [OSTI]

with a limited number of data appears as a highly underdetermined ill-posed problem. The projection data computed tomography. However, such algorithms are sensitive to noise artifacts so that the reconstruction projections that are close to the measured projection data. Iterative based ML reconstruction algorithms

Paris-Sud XI, Université de

219

Bayesian Image Reconstruction for Transmission Tomography Using Mixture Model Priors and Deterministic Annealing  

E-Print Network [OSTI]

degradations in emission computed tomography (ECT) for both PET and SPECT. To improve quantitative accuracy transmission projection data. However, the transmission projection data is itself usually very noisy due to the necessities of a short-time acquisition and limited count rate . The low-count data makes the reconstruction

220

Line-source based X-ray Tomography Deepak Bharkhada1,2  

E-Print Network [OSTI]

resolution is limited by the time necessary to acquire sufficient projection data over an angular range. #12 Science, Wake Forest University, Winston-Salem, NC 27109 Abstract: Current computed tomography (CT reconstruction technique (SART) algorithm for image reconstruction from projection data generated by an x

Plemmons, Robert J.

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Degradation of Li/S Battery Electrodes Studied Using X-ray Phase Contrast Tomography  

E-Print Network [OSTI]

the Li-ion battery market. This can be explained by their high energy density, high operating voltage1 Degradation of Li/S Battery Electrodes Studied Using X-ray Phase Contrast Tomography L. Zielkea. Zengerlea,f and S. Thielea,g Lithium/sulphur batteries are promising candidates for future energy storage

Schmidt, Volker

222

VIDEO IDENTIFICATION USING VIDEO TOMOGRAPHY Gustavo Leon, Hari Kalva, and Borko Furht  

E-Print Network [OSTI]

VIDEO IDENTIFICATION USING VIDEO TOMOGRAPHY Gustavo Leon, Hari Kalva, and Borko Furht Department of Computer Science and Engineering, Florida Atlantic University, Boca Raton, FL, USA ABSTRACT Video popularity of online video services. The problem addressed in this paper is the identification of a given

Kalva, Hari

223

Group-velocity tomography of South America and the surrounding oceans  

E-Print Network [OSTI]

Group-velocity tomography of South America and the surrounding oceans Oleg Vdovin,1 Jose¨ A. Rial,2 propagating across South America and the surrounding oceans. Broad-band waveform data from about 765 events and show that the average resolution across South America is about 60^80 for Rayleigh waves and 70

Ritzwolle, Mike

224

THE VALUE OF BOREHOLE -TO-SURFACE INFORMATION IN NEAR-SURFACE CROSSWELL SEISMIC TOMOGRAPHY  

E-Print Network [OSTI]

seismic reflection cannot (e.g. Liberty et al., 1999; Musil et al., 2002). The images producedTHE VALUE OF BOREHOLE -TO-SURFACE INFORMATION IN NEAR-SURFACE CROSSWELL SEISMIC TOMOGRAPHY Geoff J properties is important in many fields. One method that can image the seismic velocity structure

Barrash, Warren

225

Soft X-ray tomography of phenotypic switching and the cellular response to antifungal peptoids  

E-Print Network [OSTI]

Soft X-ray tomography of phenotypic switching and the cellular response to antifungal peptoids that circumvent fungal drug- resistance mechanisms. In this work we used soft X-ray tomogra- phy to image of an entire, fully functional biological system, i.e., in the milieu of a cell (8, 10). Recently, soft X-ray

Barron, Annelise E.

226

Algorithms for Fluorescence Lifetime Microscopy and Optical Coherence Tomography Data Analysis: Applications for Diagnosis of Atherosclerosis and Oral Cancer  

E-Print Network [OSTI]

imaging (FLIM) with optical coherence tomography (OCT), for the diagnosis of atherosclerosis and oral cancer. FLIM is a fluorescence imaging technique that is capable of providing information about auto fluorescent tissue biomolecules. OCT on the other...

Pande, Paritosh

2014-05-16T23:59:59.000Z

227

Simultaneous maximum-likelihood reconstruction for x-ray grating based phase-contrast tomography avoiding intermediate phase retrieval  

E-Print Network [OSTI]

Phase-wrapping artifacts, statistical image noise and the need for a minimum amount of phase steps per projection limit the practicability of x-ray grating based phase-contrast tomography, when using filtered back projection reconstruction. For conventional x-ray computed tomography, the use of statistical iterative reconstruction algorithms has successfully reduced artifacts and statistical issues. In this work, an iterative reconstruction method for grating based phase-contrast tomography is presented. The method avoids the intermediate retrieval of absorption, differential phase and dark field projections. It directly reconstructs tomographic cross sections from phase stepping projections by the use of a forward projecting imaging model and an appropriate likelihood function. The likelihood function is then maximized with an iterative algorithm. The presented method is tested with tomographic data obtained through a wave field simulation of grating based phase-contrast tomography. The reconstruction result...

Ritter, André; Durst, Jürgen; Gödel, Karl; Haas, Wilhelm; Michel, Thilo; Rieger, Jens; Weber, Thomas; Wucherer, Lukas; Anton, Gisela

2013-01-01T23:59:59.000Z

228

Neutron Computed Tomography of Freeze/thaw Phenomena in Polymer Electrolyte Fuel Cells  

SciTech Connect (OSTI)

This report summarizes the final year's progress of the three-year NEER program. The overall objectives of this program were to 1) design and construct a sophisticated hight-resolution neutron computed tomography (NCT) facility, 2) develop novel and sophisticated liquid water and ice quantification analysis software for computed tomography, and 3) apply the advanced software and NCT capability to study liquid and ice distribution in polymer electrolyte fuel cells (PEFCs) under cold-start conditions. These objectives have been accomplished by the research team, enabling a new capability for advanced 3D image quantification with neutron imaging for fuel cell and other applications. The NCT water quantification methodology and software will greatly add to the capabilities of the neutron imaging community, and the quantified liquid water and ice distribution provided by its application to PEFCs will enhance understanding and guide design in the fuel cell community.

Matthew M. Mech; Jack Brenizer; Kenan Unlu; A.K. Heller

2008-12-12T23:59:59.000Z

229

Retrieving the 3D matter power spectrum and galaxy biasing parameters from lensing tomography  

E-Print Network [OSTI]

With the availability of galaxy distance indicators in weak lensing surveys, lensing tomography can basically be harnessed to constrain the spatial 3D matter power spectrum over a range in redshift and physical scale. Furthermore, by adding galaxy-galaxy lensing and galaxy clustering this can be extended to probe the 3D galaxy-matter and galaxy-galaxy power spectrum or, alternatively, galaxy biasing parameters. To achieve this aim, this paper introduces and discusses minimum variance estimators and a more general Bayesian approach to statistically invert a set of noisy tomography 2-point correlation functions, measured within a confined opening angle. Both methods are constructed such that they probe deviations of the 3D power spectrum from a fiducial power spectrum. Thereby a direct comparison of theory and data is achieved, the physical scale and redshift of deviations can in principle be identified. By devising a new Monte Carlo technique the measurement noise in the correlators is quantified for a fiducia...

Simon, Patrick

2012-01-01T23:59:59.000Z

230

Quantum process tomography and Linblad estimation of a solid state qubit  

E-Print Network [OSTI]

We present an example of quantum process tomography (QPT) performed on a single solid state qubit. The qubit used is two energy levels of the triplet state in the Nitrogen-Vacancy defect in Diamond. Quantum process tomography is applied to a qubit which has been allowed to decohere for three different time periods. In each case the process is found in terms of the chi matrix representation and the affine map representation. The discrepancy between experimentally estimated process and the closest physically valid process is noted. The results of QPT performed after three different decoherence times are used to find the error generators, or Lindblad operators, for the system, using the technique introduced by Boulant et al. [N. Boulant, T.F. Havel, M.A. Pravia and D.G. Cory, Phys. Rev. A 67, 042322 (2003)].

M. Howard; J. Twamley; C. Wittmann; T. Gaebel; F. Jelezko; J. Wrachtrup

2006-01-25T23:59:59.000Z

231

A simple setup for neutron tomography at the Portuguese Nuclear Research Reactor  

E-Print Network [OSTI]

A simple setup for neutron radiography and tomography was recently installed at the Portuguese Research Reactor. The objective of this work was to determine the operational characteristics of the installed setup, namely the irradiation time to obtain the best dynamic range for individual images and the spatial resolution. The performance of the equipment was demonstrated by imaging a fragment of a 17th century decorative tile.

M. A. Stanojev Pereira; J. G. Marques; R. Pugliesi

2012-05-15T23:59:59.000Z

232

Vacuum photodiode detectors for soft x-ray ITER plasma tomography  

SciTech Connect (OSTI)

A special type of vacuum photodiode detector (VPD) for x-ray tomography of (ITER) plasma is described. Laboratory experiments demonstrate that VPD has high sensitivity to thermal x-rays and low sensitivity to hard gamma rays and neutrons. It was shown that in ITER environment the signal due to thermal x-rays will surpass the background signal by more than a factor of 100.

Gott, Yu.V.; Stepanenko, M.M. [RRC, Nuclear Fusion Institute, Kurchatov sq.1, Moscow, 123182 (Russian Federation)

2005-07-15T23:59:59.000Z

233

Measurement of bubble sizes in fluidised beds using electrical capacitance tomography  

E-Print Network [OSTI]

-mail address: djh79@cam.ac.uk (D.J. Holland). 1 Now at the Ocean Science & Technology Division, Graduate School at Shenzhen, Tsinghua University, China. 2 Now at the Department of Chemical and Process Engineering, University of Canterbury, Christchurch, New... Measurement of bubble sizes in fluidised beds using electrical capacitance tomography T.C. Chandrasekera, Y. Li 1, D. Moody, M.A. Schnellmann, J.S. Dennis, D.J. Holland n,2 Department of Chemical Engineering and Biotechnology, University...

Chandrasekera, T. C.; Li, Y.; Moody, D.; Schnellmann, M. A.; Dennis, J. S.; Holland, D. J.

2015-01-13T23:59:59.000Z

234

Barium Titanate Nanoparticles as Exogenous Contrast Agents in Second Harmonic Optical Coherence Tomography  

E-Print Network [OSTI]

fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, Brian Applegate Committee Members, Kristen Maitland Jim Ji Head of Department, Gerard Cote May 2013 Major Subject: Biomedical Engineering...-OCT without producing inferior reflector artifacts. 38 REFERENCES Applegate, Brian. (2004). Polarization-resolved Second-harmonic-generation Optical Coherence Tomography in Collagen. Optics Letters, 29(19), 2252-2254. H?usler G., Lindner M. W...

Pearson, Jeremy T

2013-05-06T23:59:59.000Z

235

On single qubit quantum process tomography for trace-preserving and nontrace-preserving maps  

E-Print Network [OSTI]

We review single-qubit quantum process tomography for trace-preserving and nontrace-preserving processes, and derive explicit forms of the general constraints for fitting experimental data. These forms provide additional insight into the structure of the process matrix as well as reveal a tighter bound on the trace of a nontrace-preserving process than has been previously stated. We also describe, for completeness, how to incorporate measured imperfect input states.

Ramesh Bhandari; Nicholas A. Peters

2015-02-03T23:59:59.000Z

236

3D and 4D magnetic susceptibility tomography based on complex MR images  

DOE Patents [OSTI]

Magnetic susceptibility is the physical property for T2*-weighted magnetic resonance imaging (T2*MRI). The invention relates to methods for reconstructing an internal distribution (3D map) of magnetic susceptibility values, .chi. (x,y,z), of an object, from 3D T2*MRI phase images, by using Computed Inverse Magnetic Resonance Imaging (CIMRI) tomography. The CIMRI technique solves the inverse problem of the 3D convolution by executing a 3D Total Variation (TV) regularized iterative convolution scheme, using a split Bregman iteration algorithm. The reconstruction of .chi. (x,y,z) can be designed for low-pass, band-pass, and high-pass features by using a convolution kernel that is modified from the standard dipole kernel. Multiple reconstructions can be implemented in parallel, and averaging the reconstructions can suppress noise. 4D dynamic magnetic susceptibility tomography can be implemented by reconstructing a 3D susceptibility volume from a 3D phase volume by performing 3D CIMRI magnetic susceptibility tomography at each snapshot time.

Chen, Zikuan; Calhoun, Vince D

2014-11-11T23:59:59.000Z

237

Positron Emission Tomography/Computed Tomography Imaging of Residual Skull Base Chordoma Before Radiotherapy Using Fluoromisonidazole and Fluorodeoxyglucose: Potential Consequences for Dose Painting  

SciTech Connect (OSTI)

Purpose: To detect the presence of hypoxic tissue, which is known to increase the radioresistant phenotype, by its uptake of fluoromisonidazole (18F) (FMISO) using hybrid positron emission tomography/computed tomography (PET/CT) imaging, and to compare it with the glucose-avid tumor tissue imaged with fluorodeoxyglucose (18F) (FDG), in residual postsurgical skull base chordoma scheduled for radiotherapy. Patients and Methods: Seven patients with incompletely resected skull base chordomas were planned for high-dose radiotherapy (dose {>=}70 Gy). All 7 patients underwent FDG and FMISO PET/CT. Images were analyzed qualitatively by visual examination and semiquantitatively by computing the ratio of the maximal standardized uptake value (SUVmax) of the tumor and cerebellum (T/C R), with delineation of lesions on conventional imaging. Results: Of the eight lesion sites imaged with FDG PET/CT, only one was visible, whereas seven of nine lesions were visible on FMISO PET/CT. The median SUVmax in the tumor area was 2.8 g/mL (minimum 2.1; maximum 3.5) for FDG and 0.83 g/mL (minimum 0.3; maximum 1.2) for FMISO. The T/C R values ranged between 0.30 and 0.63 for FDG (median, 0.41) and between 0.75 and 2.20 for FMISO (median,1.59). FMISO T/C R >1 in six lesions suggested the presence of hypoxic tissue. There was no correlation between FMISO and FDG uptake in individual chordomas (r = 0.18, p = 0.7). Conclusion: FMISO PET/CT enables imaging of the hypoxic component in residual chordomas. In the future, it could help to better define boosted volumes for irradiation and to overcome the radioresistance of these lesions. No relationship was founded between hypoxia and glucose metabolism in these tumors after initial surgery.

Mammar, Hamid, E-mail: hamid.mammar@unice.fr [Radiation Oncology Department, Antoine Lacassagne Center, Nice (France) [Radiation Oncology Department, Antoine Lacassagne Center, Nice (France); CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Kerrou, Khaldoun; Nataf, Valerie [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)] [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France); Pontvert, Dominique [Proton Therapy Center of Orsay, Curie Institute, Paris (France)] [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Clemenceau, Stephane [Department of Neurosurgery, Pitie-Salpetriere Hospital, Paris (France)] [Department of Neurosurgery, Pitie-Salpetriere Hospital, Paris (France); Lot, Guillaume [Department of Neurosurgery, Adolph De Rothschild Foundation, Paris (France)] [Department of Neurosurgery, Adolph De Rothschild Foundation, Paris (France); George, Bernard [Department of Neurosurgery, Lariboisiere Hospital, Paris (France)] [Department of Neurosurgery, Lariboisiere Hospital, Paris (France); Polivka, Marc [Department of Pathology, Lariboisiere Hospital, Paris (France)] [Department of Pathology, Lariboisiere Hospital, Paris (France); Mokhtari, Karima [Department of Pathology, Pitie-Salpetriere Hospital, Paris (France)] [Department of Pathology, Pitie-Salpetriere Hospital, Paris (France); Ferrand, Regis; Feuvret, Loiec; Habrand, Jean-louis [Proton Therapy Center of Orsay, Curie Institute, Paris (France)] [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Pouyssegur, Jacques; Mazure, Nathalie [CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France)] [CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Talbot, Jean-Noeel [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)] [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)

2012-11-01T23:59:59.000Z

238

High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography  

DOE Patents [OSTI]

This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

Olivier, Scot S. (Livermore, CA); Werner, John S. (Davis, CA); Zawadzki, Robert J. (Sacramento, CA); Laut, Sophie P. (Pasedena, CA); Jones, Steven M. (Livermore, CA)

2010-09-07T23:59:59.000Z

239

Phase contrast tomography of the mouse cochlea at microfocus x-ray sources  

SciTech Connect (OSTI)

We present phase contrast x-ray tomography of functional soft tissue within the bony cochlear capsule of mice, carried out at laboratory microfocus sources with well-matched source, detector, geometry, and reconstruction algorithms at spatial resolutions down to 2 ?m. Contrast, data quality and resolution enable the visualization of thin membranes and nerve fibers as well as automated segmentation of surrounding bone. By complementing synchrotron radiation imaging techniques, a broad range of biomedical applications becomes possible as demonstrated for optogenetic cochlear implant research.

Bartels, Matthias; Krenkel, Martin [Institute for X-Ray Physics, University of Göttingen, Göttingen (Germany)] [Institute for X-Ray Physics, University of Göttingen, Göttingen (Germany); Hernandez, Victor H. [InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, Göttingen (Germany) [InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, Göttingen (Germany); Bernstein Focus for Neurotechnology, University of Göttingen, Göttingen (Germany); Moser, Tobias [InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, Göttingen (Germany) [InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, Göttingen (Germany); Bernstein Focus for Neurotechnology, University of Göttingen, Göttingen (Germany); Center for Nanoscopy and Molecular Physiology of the Brain, Göttingen (Germany); Salditt, Tim [Institute for X-Ray Physics, University of Göttingen, Göttingen (Germany) [Institute for X-Ray Physics, University of Göttingen, Göttingen (Germany); Center for Nanoscopy and Molecular Physiology of the Brain, Göttingen (Germany)

2013-08-19T23:59:59.000Z

240

Positron Emission Tomography-Scanner at Children`s Hospital of Michigan at Detroit, Michigan  

SciTech Connect (OSTI)

The Department of Energy has prepared an environmental assessment (EA), DOE/EA-0795, to support the DOE decision to provide a grant of $7,953,600 to be used in support of a proposed Positron Emission Tomography Scanner at Children`s Hospital of Michigan at Detroit, Michigan. Based upon the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affected the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).

Not Available

1992-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

New Cyclotron Targetry to Enhance F-18 clinical Position Emission Tomography  

SciTech Connect (OSTI)

This project proposes to develop cyclotron targets that produce F-18 for clinical Positron Emission Tomography (PET) at significantly higher rates than that available from current targetry. This production rate of 18F is directly proportional to the beam current. Higher beam currents would result in increased 18F production but would be accompanied by higher heat loads to the target. The beam power available in most commercial cyclotrons exceeds the heat removal capacity of current target technology by a factor of two to four, significantly limiting the production rate of Fluorine-18.

J. Michael Doster

2008-12-19T23:59:59.000Z

242

X-ray Computed Tomography of the Root System of a Live Potted Plant | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched FerromagnetismWaste and MaterialsWenjun1of EnergyX-ray Computed Tomography of the

243

Electrical impedance tomography spectroscopy method for characterising particles in solid-liquid phase  

SciTech Connect (OSTI)

Electrical impedance tomography (EIT) is one of the process tomography techniques to provide an on-line non-invasive imaging for multiphase flow measurement. With EIT measurements, the images of impedance real part, impedance imaginary part, phase angle, and magnitude can be obtained. However, most of the applications of EIT in the process industries rely on the conductivity difference between two phases in fluids to obtain the concentration profiles. It is not common to use the imaginary part or phase angle due to the dominant change in conductivity or complication in the use of other impedance information. In a solid-liquid two phases system involving nano- or submicro-particles, characterisation of particles (e.g. particle size and concentration) have to rely on the measurement of impedance phase angle or imaginary part. Particles in a solution usually have an electrical double layer associated with their surfaces and can form an induced electrical dipole moment due to the polarization of the electrical double layer under the influence of an alternating electric field. Similar to EIT, electrical impedance spectroscopy (EIS) measurement can record the electrical impedance data, including impedance real part, imaginary part and phase angle (?), which are caused by the polarization of the electrical double layer. These impedance data are related to the particle characteristics e.g. particle size, particle and ionic concentrations in the aqueous medium, therefore EIS method provides a capability for characterising the particles in suspensions. Electrical impedance tomography based on EIS measurement or namely, electrical impedance tomography spectroscopy (EITS) could image the spatial distribution of particle characteristics. In this paper, a new method, including test set-up and data analysis, for characterisation of particles in suspensions are developed through the experimental approach. The experimental results on tomographic imaging of colloidal particles based on EIS measurement using a sensor of 8 electrodes are reported. Results have demonstrated the potential as well as revealed the challenge in the use of EIS and EITS for characterisation of particle in suspension.

Zhao, Yanlin [Department of Thermal Energy Engineering, College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing, 102249 (China); Wang, Mi [Institute of Particle Science and Engineering, School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT (China); Yao, Jun [School of Energy Research, Xiamen University, Xiamen 361005 (China)

2014-04-11T23:59:59.000Z

244

THE SLOAN DIGITAL SKY SURVEY CO-ADD: CROSS-CORRELATION WEAK LENSING AND TOMOGRAPHY OF GALAXY CLUSTERS  

SciTech Connect (OSTI)

The shapes of distant galaxies are sheared by intervening galaxy clusters. We examine this effect in Stripe 82, a 275 deg{sup 2} region observed multiple times in the Sloan Digital Sky Survey (SDSS) and co-added to achieve greater depth. We obtain a mass-richness calibration that is similar to other SDSS analyses, demonstrating that the co-addition process did not adversely affect the lensing signal. We also propose a new parameterization of the effect of tomography on the cluster lensing signal which does not require binning in redshift, and we show that using this parameterization we can detect tomography for stacked clusters at varying redshifts. Finally, due to the sensitivity of the tomographic detection to accurately marginalize over the effect of the cluster mass, we show that tomography at low redshift (where dependence on exact cosmological models is weak) can be used to constrain mass profiles in clusters.

Simet, Melanie; Dodelson, Scott [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Kubo, Jeffrey M.; Annis, James T.; Hao Jiangang; Johnston, David; Lin, Huan; Soares-Santos, Marcelle [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Reis, Ribamar R. R. [Instituto de Fisica, Universidade Federal do Rio de Janeiro (Brazil); Seo, Hee-Jong [Berkeley Center for Cosmological Physics and Berkeley Lab, University of California, Berkeley, CA 94720 (United States)

2012-04-01T23:59:59.000Z

245

Using seismic tomography to characterize fracture systems induced by hydraulic fracturing  

SciTech Connect (OSTI)

Microearthquakes induced by hydraulic fracturing have been studied by many investigators to characterize fracture systems created by the fracturing process and to better understand the locations of energy resources in the earth`s subsurface. The pattern of the locations often contains a great deal of information about the fracture system stimulated during the hydraulic fracturing. Seismic tomography has found applications in many areas for characterizing the subsurface of the earth. It is well known that fractures in rock influence both the P and S velocities of the rock. The influence of the fractures is a function of the geometry of the fractures, the apertures and number of fractures, and the presence of fluids in the fractures. In addition, the temporal evolution of the created fracture system can be inferred from the temporal changes in seismic velocity and the pattern of microearthquake locations. Seismic tomography has been used to infer the spatial location of a fracture system in a reservoir that was created by hydraulic fracturing.

Fehler, M.; Rutledge, J.

1995-01-01T23:59:59.000Z

246

Compact cold stage for micro-computerized tomography imaging of chilled or frozen samples  

SciTech Connect (OSTI)

High resolution X-ray microCT (computerized tomography) can be used to image a variety of objects, including temperature-sensitive materials. In cases where the sample must be chilled or frozen to maintain sample integrity, either the microCT machine itself must be placed in a refrigerated chamber, or a relatively expensive commercial cold stage must be purchased. We describe here the design and construction of a low-cost custom cold stage suitable for use in a microCT imaging system. Our device uses a boron nitride sample holder, two-stage Peltier cooler, fan-cooled heat sink, and electronic controller to maintain sample temperatures as low as ?25?°C ± 0.2?°C for the duration of a tomography acquisition. The design does not require modification to the microCT machine, and is easily installed and removed. Our custom cold stage represents a cost-effective solution for refrigerating CT samples for imaging, and is especially useful for shared equipment or machines unsuitable for cold room use.

Hullar, Ted; Anastasio, Cort, E-mail: canastasio@ucdavis.edu [Department of Land, Air, and Water Resources, University of California, Davis, California 95616 (United States)] [Department of Land, Air, and Water Resources, University of California, Davis, California 95616 (United States); Paige, David F. [Paige Instruments, Woodland, California 95776 (United States)] [Paige Instruments, Woodland, California 95776 (United States); Rowland, Douglas J. [Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California, Davis, California 95616 (United States)] [Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California, Davis, California 95616 (United States)

2014-04-15T23:59:59.000Z

247

Computed tomography of coals. Quarterly technical progress report No. 1, August 16, 1982-November 28, 1982  

SciTech Connect (OSTI)

The purpose of this contract is to examine the utility and advantages of x-ray computed tomography (CT) for investigating the structure within coal and the changes that occur in these structures during such processes as combustion and gasification. The CT technique is noninvasive and nondestructive. It can produce interior views of the coal and, with a data acquisition time of ca 9 seconds, can be used for following many coal processes in real time. This is the first in-depth study of the application of the x-ray tomography technique to the problems in coal utilization, and consequently, considerable time will be spent in the early stages of this contract in examining CT pictures of coal and relating them to more conventional petrographic and mineral analyses. This phase of the work is being undertaken in Task 1 of the contract and is reported for this period. Building on this foundation, the succeeding tasks will follow changes in the coal structure during reaction. The first series of CT experiments is scheduled to take place on December 11-13, 1982, at the General Electric Company, Medical Systems Operation, Milwaukee, Wisconsin. 4 figures, 1 table.

Maylotte, D. H.; Kosky, P. G.; Spiro, C. L.; Lamby, E. J.

1982-01-01T23:59:59.000Z

248

Study on creating hydraulic tomography for crystalline rock using frequency dependent elastic wave velocity  

SciTech Connect (OSTI)

The objective of this study is to establish a technique to obtain hydraulic conductivity distribution in granite rock masses using seismic tomography. We apply the characteristic that elastic wave velocity disperses in fully saturated porous media on frequency and this velocity dispersion is governed by the hydraulic conductivity - this characteristic has been confirmed in laboratory experiments. The feasibility and design of the field experiment was demonstrated in a first step with numerical simulations. In a second step we applied the technique to the fractured granite at the Grimsel Test Site in Switzerland. The emphasis of the field campaign was on the evaluation of the range of applicability of this technique. The field campaign was structured in three steps, each one corresponding to a larger spatial scale. First, the seismic tomography was applied to a small area - the two boreholes were located at a distance of 1.5 m. In the following step, we selected a larger area, in which the distance of the boreholes amounts to 10 m and the field corresponds to a more complex geology. Finally we applied the testing to a field where the borehole distance was of the order of 75 m. We also drilled a borehole to confirm hydraulic characteristic and reviewed hydraulic model in the 1.5 m cross-hole location area. The results from the field campaign are presented and their application to the various fields are discussed and evaluated. (authors)

Yoshimura, K.; Sakashita, S. [Radioactive Waste Management Funding and Research Center, Tokyo (Japan); Ando, K.; Bruines, P. [Civil Engineering Technical Division, Obayashi Corporation, Tokyo (Japan); Blechschmidt, I. [National Cooperative for the Disposal of Radioactive Waste, Wettingen (Switzerland); Kickmaier, W. [University of Applied Sciences, Northern Switzerland, Brugg (Switzerland); Onishi, Y.; Nishiyama, S. [Graduate School of Engineering, Kyoto University, Kyoto (Japan)

2007-07-01T23:59:59.000Z

249

Time-frequency quantum process tomography of parametric down-conversion  

E-Print Network [OSTI]

Parametric down-conversion (PDC) is the established standard for the practical generation of a multiplicity of quantum optical states. These include two-mode squeezed vacuum, heralded non-Gaussian states and entangled photon pairs. Detailed theoretical studies provide insight into the time-frequency (TF) structure of PDC, which are governed by the complex-valued joint spectral amplitude (JSA) function. However in experiments, the TF structure of PDC is mostly characterised by intensity measurementsthat forbid access to the important phase of the JSA. In this paper, we present an amplitude-sensitive quantum process tomography technique that combines methods from ultrafast optics and classical three-wave mixing. Our approach facilitates a direct and phase-sensitive time-frequency tomography of PDC with high spectral resolution and excellent signal-to-noise ratio. This is important for all quantum optical applications, which rely on engineered parametric processes and base on minute knowledge of the quantum wave-function for the generation of tailored photonic quantum states.

Malte Avenhaus; Benjamin Brecht; Kaisa Laiho; Christine Silberhorn

2014-06-17T23:59:59.000Z

250

Simulation of electron-matter interaction during wet-STEM electron tomography  

SciTech Connect (OSTI)

Tomography is an efficient tool to probe the 3 dimensional (3D) structure of materials. In the laboratory, a device has been developed to perform electron tomography in an environmental scanning electron microscopy (ESEM). The configuration of Scanning Transmission Electron Microscopy (STEM) in Environmental Scanning Electron Microscopy (ESEM) provides a novel approach for the characterization of the 3D structure of materials and optimizes a compromise between the resolution level of a few nm and the large tomogram due to the high thickness of transparency. Moreover, STEM allows the observation in 2D of wet samples in an ESEM by finely controlling the sample temperature and the water pressure of the sample environment. It has been recently demonstrated that it was possible to acquire image series of hydrated objects and thus to attain 3D characterization of wet samples. In order to get reliable and quantitative data, the present study deals with the simulation of electron-matter interactions. From such simulation on the MCM-41 material, we determine the minimum quantity of water layer which can be detected on wet materials.

Septiyanto, Rahmat Firman, E-mail: karine.masenelli-varlot@insa-lyon.fr [MATEIS, INSA-Lyon, CNRS UMR5510, F-69621, France and Physics of Electronic Material, Departement of Physics, Faculty of Mathematic and Natural Sciences, ITB Jalan Ganesha No. 10, Bandung 40132 (Indonesia); Masenelli-Varlot, Karine [MATEIS, INSA-Lyon, CNRS UMR5510, F-69621 (France); Iskandar, Ferry [Physics of Electronic Material, Departement of Physics, Faculty of Mathematic and Natural Sciences, ITB Jalan Ganesha No. 10, Bandung 40132 (Indonesia)

2014-02-24T23:59:59.000Z

251

Double-Difference Tomography for Sequestration MVA [monitoring, verification, and accounting  

SciTech Connect (OSTI)

Analysis of synthetic data was performed to determine the most cost-effective tomographic monitoring system for a geologic carbon sequestration injection site. Double-difference tomographic inversion was performed on 125 synthetic data sets: five stages of CO2 plume growth, five seismic event regions, and five geophone arrays. Each resulting velocity model was compared quantitatively to its respective synthetic velocity model to determine an accuracy value. The results were examined to determine a relationship between cost and accuracy in monitoring, verification, and accounting applications using double-difference tomography. The geophone arrays with widely-varying geophone locations, both laterally and vertically, performed best. Additionally, double difference seismic tomography was performed using travel time data from a carbon sequestration site at the Aneth oil field in southeast Utah as part of a Department of Energy initiative on monitoring, verification, and accounting (MVA) of sequestered CO2. A total of 1,211 seismic events were recorded from a borehole array consisting of 22 geophones. Artificial velocity models were created to determine the ease with which different CO2 plume locations and sizes can be detected. Most likely because of the poor geophone arrangement, a low velocity zone in the Desert Creek reservoir can only be detected when regions of test site containing the highest ray path coverage are considered. MVA accuracy and precision may be improved through the use of a receiver array that provides more comprehensive ray path coverage.

Westman, Erik

2012-12-31T23:59:59.000Z

252

Electrical impedance tomography of carbon nanotube composite Tsung-Chin Hou, Kenneth J. Loh, Jerome P. Lynch1  

E-Print Network [OSTI]

Electrical impedance tomography of carbon nanotube composite materials Tsung-Chin Hou, Kenneth J composites with the carbon nanotube significantly contributing to bulk material properties. One approach. Carbon nanotubes are included in the composite material by dispersing them in the polyanionic solution

Lynch, Jerome P.

253

Experimental comparison of grating- and propagation-based hard X-ray phase tomography of soft tissue  

SciTech Connect (OSTI)

When imaging soft tissues with hard X-rays, phase contrast is often preferred over conventional attenuation contrast due its superior sensitivity. However, it is unclear which of the numerous phase tomography methods yields the optimized results at given experimental conditions. Therefore, we quantitatively compared the three phase tomography methods implemented at the beamline ID19 of the European Synchrotron Radiation Facility: X-ray grating interferometry (XGI), and propagation-based phase tomography, i.e., single-distance phase retrieval (SDPR) and holotomography (HT), using cancerous tissue from a mouse model and an entire heart of a rat. We show that for both specimens, the spatial resolution derived from the characteristic morphological features is about a factor of two better for HT and SDPR compared to XGI, whereas the XGI data generally exhibit much better contrast-to-noise ratios for the anatomical features. Moreover, XGI excels in fidelity of the density measurements, and is also more robust against low-frequency artifacts than HT, but it might suffer from phase-wrapping artifacts. Thus, we can regard the three phase tomography methods discussed as complementary. The application will decide which spatial and density resolutions are desired, for the imaging task and dose requirements, and, in addition, the applicant must choose between the complexity of the experimental setup and the one of data processing.

Lang, S.; Schulz, G.; Müller, B. [Biomaterials Science Center, University of Basel, Basel (Switzerland); Zanette, I., E-mail: irene.zanette@tum.de [Physik-Department und Institut für Medizintechnik, Technische Universität München, Garching (Germany); European Synchrotron Radiation Facility, Grenoble (France); Dominietto, M. [Biomaterials Science Center, University of Basel, Basel (Switzerland); Institute for Biomedical Engineering, ETH Zürich, Zürich (Switzerland); Langer, M. [European Synchrotron Radiation Facility, Grenoble (France); Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-LYON, Université de Lyon 1, Villeurbane (France); Rack, A.; Le Duc, G. [European Synchrotron Radiation Facility, Grenoble (France); David, C. [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, Villigen (Switzerland); Mohr, J. [Institute of Microstructure Technology, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen (Germany); Pfeiffer, F. [Physik-Department und Institut für Medizintechnik, Technische Universität München, Garching (Germany); Weitkamp, T. [European Synchrotron Radiation Facility, Grenoble (France); Synchrotron Soleil, Gif-sur-Yvette (France)

2014-10-21T23:59:59.000Z

254

Reply to comment on "Electrical Tomography of La Soufrire of Guadeloupe Volcano: Field experiments, 1D inversion and  

E-Print Network [OSTI]

Discussion Reply to comment on "Electrical Tomography of La Soufrière of Guadeloupe Volcano: Field.25.Qi; 91.35.Pn; 91.40.-k; 93.30.Vs 1. Introduction We thank Linde and Revil for their comment [1 and discuss our approach for interpreting electrical resistivity data acquired over complex geological

Beauducel, François

255

Fluorescence optical diffusion tomography Adam B. Milstein, Seungseok Oh, Kevin J. Webb, Charles A. Bouman, Quan Zhang,  

E-Print Network [OSTI]

tomography ODT is emerging as a powerful tissue imaging modality.1,2 In ODT, im- ages are comprised sources and detectors are used to recover the unknown parame- ters from a scattering model described to diffusion model computations. As a result of the nonlinear dependence of the diffusion equation photon flux

256

Neutron tomography of axisymmetric flow fields in porous media A.J. Gilbert, M.R. Deinert  

E-Print Network [OSTI]

Neutron tomography of axisymmetric flow fields in porous media A.J. Gilbert, M.R. Deinert February 2013 Keywords: Preferential flow Wetting front Neutron radiography Image analysis Fingered flow axisymmetric preferential flow fields using neutron radiography. Flow fields such as these are surprisingly

Deinert, Mark

257

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

SciTech Connect (OSTI)

In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

2012-01-10T23:59:59.000Z

258

Link between Tomography and Copula1 Doriano-Boris Pougaza, Ali Mohammad-Djafari, Jean-Francois Bercher2  

E-Print Network [OSTI]

in Computed To- mography (CT) is to reconstruct an image from its projections. In the bivariate case of Environmental Data [2, 3]. Recently, in17 Computational Biology, copulas were used for the reconstructionLink between Tomography and Copula1 Doriano-Boris Pougaza, Ali Mohammad-Djafari, Jean

Bercher, Jean-François

259

BRUCE HOWE Chair and Professor , PhD 1986, UC San Diego. Ocean observatories, ocean acoustic tomography, sensor webs  

E-Print Network [OSTI]

. NIHOUS Associate Professor, PhD 1983, UC Berkeley. Ocean Thermal Energy Conversion (OTEC), marineFaculty BRUCE HOWE Chair and Professor , PhD 1986, UC San Diego. Ocean observatories, ocean in the ocean, atmospheric and ionospheric tomography. KWOK FAI CHEUNG Professor , PhD 1991, British Columbia

Frandsen, Jannette B.

260

Multislice Spiral Computed Tomography of the Heart: Technique, Current Applications, and Perspective  

SciTech Connect (OSTI)

Multislice spiral computed tomography (MSCT) is a rapidly evolving, noninvasive technique for cardiac imaging. Knowledge of the principle of electrocardiogram-gated MSCT and its limitations in clinical routine are needed to optimize image quality. Therefore, the basic technical principle including essentials of image postprocessing is described. Cardiac MSCT imaging was initially focused on coronary calcium scoring, MSCT coronary angiography, and analysis of left ventricular function. Recent studies also evaluated the ability of cardiac MSCT to visualize myocardial infarction and assess valvular morphology. In combination with experimental approaches toward the assessment of aortic valve function and myocardial viability, cardiac MSCT holds the potential for a comprehensive examination of the heart using one single examination technique.

Mahnken, Andreas H., E-mail: mahnken@rad.rad.rwth-aachen.de; Wildberger, Joachim E. [Aachen University of Technology, Department of Diagnostic Radiology (Germany); Koos, Ralf [Aachen University of Technology, Medical Clinic I (Germany); Guenther, Rolf W. [Aachen University of Technology, Department of Diagnostic Radiology (Germany)

2005-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
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261

Expectation propagation for nonlinear inverse problems – with an application to electrical impedance tomography  

SciTech Connect (OSTI)

In this paper, we study a fast approximate inference method based on expectation propagation for exploring the posterior probability distribution arising from the Bayesian formulation of nonlinear inverse problems. It is capable of efficiently delivering reliable estimates of the posterior mean and covariance, thereby providing an inverse solution together with quantified uncertainties. Some theoretical properties of the iterative algorithm are discussed, and the efficient implementation for an important class of problems of projection type is described. The method is illustrated with one typical nonlinear inverse problem, electrical impedance tomography with complete electrode model, under sparsity constraints. Numerical results for real experimental data are presented, and compared with that by Markov chain Monte Carlo. The results indicate that the method is accurate and computationally very efficient.

Gehre, Matthias, E-mail: mgehre@math.uni-bremen.de [Center for Industrial Mathematics, University of Bremen, Bremen D-28344 (Germany)] [Center for Industrial Mathematics, University of Bremen, Bremen D-28344 (Germany); Jin, Bangti, E-mail: bangti.jin@gmail.com [Department of Mathematics, University of California, Riverside, University Ave. 900, Riverside, CA 92521 (United States)] [Department of Mathematics, University of California, Riverside, University Ave. 900, Riverside, CA 92521 (United States)

2014-02-15T23:59:59.000Z

262

Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium  

DOE Patents [OSTI]

A method and apparatus are described for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

Beller, L.S.

1993-01-26T23:59:59.000Z

263

X-ray tomography system to investigate granular materials during mechanical loading  

E-Print Network [OSTI]

We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in-situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3d computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3d-printed particles, we resolve packing features with 0.52 mm resolution in a (60 mm)$^3$ field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

Athanassiadis, Athanasios G; Sidky, Emil; Pelizzari, Charles; Pan, Xiaochuan; Jaeger, Heinrich M

2014-01-01T23:59:59.000Z

264

Three-dimensional Chemical Imaging of Embedded Nanoparticles using Atom Probe Tomography  

SciTech Connect (OSTI)

Analysis of nanoparticles is often challenging especially when they are embedded in a matrix. Hence, we have used laser-assisted atom probe tomography (APT) to analyze the Au-nanoclusters synthesized in situ using ion beam implantation in single crystal MgO matrix. APT analysis along with scanning transmission electron microscopy and energy dispersive spectroscopy (STEM-EDS) indicated that the nanoparticles have an average size ~ 8 - 12 nm. While it is difficult to analyze the composition of individual nanoparticles using STEM, APT analysis can give three dimensional compositions of the same. It was shown that the maximum Au-concentration in the nanoparticles increases with increasing particle size, with a maximum Au-concentration of up to 50%.

Kuchibhatla, Satyanarayana V N T; Shutthanandan, V.; Prosa, Ty J.; Adusumilli, Praneet; Arey, Bruce W.; Buxbaum, Alex; Wang, Y. C.; Tessner, Ted; Ulfig, Robert M.; Wang, Chong M.; Thevuthasan, Suntharampillai

2012-05-03T23:59:59.000Z

265

X-Ray Microscopy at BESSY: From Nano-Tomography to Fs-Imaging  

SciTech Connect (OSTI)

The BESSY X-ray microscopy group has developed a new full-field x-ray microscope with glass capillary condenser. It permits tomography and spectromicroscopy of cryogenic as well as heated samples. Correlative light and x-ray microscopy is supported by an incorporated high resolution light microscope. Spectromicroscopy with polarized x-rays from a helical undulator can be performed with E/{delta}E = 104. With the planned BESSY High Gain Harmonic Generation Free Electron Laser (HGHG-FEL) x-ray imaging with ultra-short pulses and an integral photon flux of about 1011 photons/pulse in an energy bandwidth of 0.1% will be possible. Single shot imaging with a full field Transmission X-ray Microscope (TXM) employing a beam shaper as a condenser will be feasible with 20 fs pulses.

Schneider, G.; Heim, S.; Rehbein, S.; Eichert, D. [BESSY GmbH, Albert Einstein Strasse 15, 12489 Berlin (Germany); Guttmann, P. [IRP, c/o BESSY m.b.H., Albert Einstein Strasse 15, 12489 Berlin (Germany); Niemann, B. [IRP, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

2007-01-19T23:59:59.000Z

266

Quantum state tomography of orbital angular momentum photonics qubits via a projection-based technique  

E-Print Network [OSTI]

While measuring the orbital angular momentum state of bright light beams can be performed using imaging techniques, a full characterization at the single-photon level is challenging. For applications to quantum optics and quantum information science, such characterization is an essential capability. Here, we present a setup to perform the quantum state tomography of photonic qubits encoded in this degree of freedom. The method is based on a projective technique using spatial mode projection via fork holograms and single-mode fibers inserted into an interferometer. The alignment and calibration of the device is detailed as well as the measurement sequence to reconstruct the associated density matrix. Possible extensions to higher-dimensional spaces are discussed.

Adrien Nicolas; Lucile Veissier; Elisabeth Giacobino; Dominik Maxein; Julien Laurat

2014-10-12T23:59:59.000Z

267

MONSTIR II: A 32-channel, multispectral, time-resolved optical tomography system for neonatal brain imaging  

SciTech Connect (OSTI)

We detail the design, construction and performance of the second generation UCL time-resolved optical tomography system, known as MONSTIR II. Intended primarily for the study of the newborn brain, the system employs 32 source fibres that sequentially transmit picosecond pulses of light at any four wavelengths between 650 and 900 nm. The 32 detector channels each contain an independent photo-multiplier tube and temporally correlated photon-counting electronics that allow the photon transit time between each source and each detector position to be measured with high temporal resolution. The system's response time, temporal stability, cross-talk, and spectral characteristics are reported. The efficacy of MONSTIR II is demonstrated by performing multi-spectral imaging of a simple phantom.

Cooper, Robert J., E-mail: robert.cooper@ucl.ac.uk; Magee, Elliott; Everdell, Nick; Magazov, Salavat; Varela, Marta; Airantzis, Dimitrios; Gibson, Adam P.; Hebden, Jeremy C. [Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT (United Kingdom)

2014-05-15T23:59:59.000Z

268

Functional optoacoustic neuro-tomography (FONT) for whole-brain monitoring of calcium indicators  

E-Print Network [OSTI]

Non-invasive observation of spatiotemporal neural activity of large neural populations distributed over entire brains is a longstanding goal of neuroscience. We developed a real-time volumetric and multispectral optoacoustic tomography platform for imaging of neural activation deep in scattering brains. The system can record 100 volumetric frames per second across a 200mm3 field of view and spatial resolutions below 70um. Experiments performed in immobilized and freely swimming larvae and in adult zebrafish brains demonstrate, for the first time, the fundamental ability to optoacoustically track neural calcium dynamics in animals labeled with genetically encoded calcium indicator GCaMP5G, while overcoming the longstanding penetration barrier of optical imaging in scattering brains. The newly developed platform offers unprecedented capabilities for functional whole-brain observations of fast calcium dynamics; in combination with optoacoustics' well-established capacity in resolving vascular hemodynamics, it co...

Sela, Gali; Deán-Ben, X Luís; Kneipp, Moritz; Ntziachristos, Vasilis; Shoham, Shy; Westmeyer, Gil G; Razansky, Daniel

2015-01-01T23:59:59.000Z

269

Atom Probe Tomography Analysis of Precipitation during Tempering of a Nanostructured Bainitic Steel  

SciTech Connect (OSTI)

Carbon distribution during tempering of a nanostructured bainitic steel was analyzed by atom probe tomography (APT). Three different types of particles are detected on samples tempered at 673 K (400 C) for 30 minutes: lower bainite cementite with a carbon content of {approx}25 at. pct, {var_epsilon}-carbides with a carbon content close to 30 at. pct, and carbon clusters, small features with a carbon content of {approx}14 at. pct indicative of a stage of tempering prior to precipitation of {var_epsilon}-carbide. After tempering at 773 K (500 C) for 30 minutes, the {var_epsilon}-carbide-to-cementite transition was observed. Solute concentration profiles across carbide/ferrite interfaces showed the distribution of substitutional elements in {var_epsilon}-carbide and cementite for all the tempering conditions.

Caballero, Francesca G. [CENIM-CSIC, Madrid, Spain; Miller, Michael K [ORNL; Garcia-Mateo, C. [CENIM-CSIC, Madrid, Spain

2011-01-01T23:59:59.000Z

270

Approximate Marginalization of Absorption and Scattering in Fluorescence Diffuse Optical Tomography  

E-Print Network [OSTI]

In fluorescence diffuse optical tomography (fDOT), the reconstruction of the fluorophore concentration inside the target body is usually carried out using a normalized Born approximation model where the measured fluorescent emission data is scaled by measured excitation data. One of the benefits of the model is that it can tolerate inaccuracy in the absorption and scattering distributions that are used in the construction of the forward model to some extent. In this paper, we employ the recently proposed Bayesian approximation error approach to fDOT for compensating for the modeling errors caused by the inaccurately known optical properties of the target in combination with the normalized Born approximation model. The approach is evaluated using a simulated test case with different amount of error in the optical properties. The results show that the Bayesian approximation error approach improves the tolerance of fDOT imaging against modeling errors caused by inaccurately known absorption and scattering of the...

Mozumder, Meghdoot; Arridge, Simon; Kaipio, Jari P; d'Andrea, Cosimo; Kolehmainen, Ville

2015-01-01T23:59:59.000Z

271

X-ray tomography system to investigate granular materials during mechanical loading  

E-Print Network [OSTI]

We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in-situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3d computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3d-printed particles, we resolve packing features with 0.52 mm resolution in a (60 mm)$^3$ field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

Athanasios G Athanassiadis; Patrick J. La Rivière; Emil Sidky; Charles Pelizzari; Xiaochuan Pan; Heinrich M. Jaeger

2014-07-28T23:59:59.000Z

272

X-ray tomography system to investigate granular materials during mechanical loading  

SciTech Connect (OSTI)

We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3D computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3D-printed particles, we resolve packing features with 0.52?mm resolution in a (60 mm){sup 3} field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

Athanassiadis, Athanasios G. [James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); La Rivière, Patrick J.; Sidky, Emil; Pan, Xiaochuan [Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Pelizzari, Charles [Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States); Jaeger, Heinrich M., E-mail: h-jaeger@uchicago.edu [James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States)

2014-08-15T23:59:59.000Z

273

Atomic Scale Characterization of Compound Semiconductors using Atom Probe Tomography: Preprint  

SciTech Connect (OSTI)

Internal interfaces are critical in determining the performance of III-V multijunction solar cells. Studying these interfaces with atomic resolution using a combination of transmission electron microscopy (TEM), atom probe tomography (APT), and density functional calculations enables a more fundamental understanding of carrier dynamics in photovoltaic (PV) device structures. To achieve full atomic scale spatial and chemical resolution, data acquisition parameters in laser pulsed APT must be carefully studied to eliminate surface diffusion. Atom probe data with minimized group V ion clustering and expected stoichiometry can be achieved by adjusting laser pulse power, pulse repetition rate, and specimen preparation parameters such that heat flow away from the evaporating surface is maximized. Applying these improved analysis conditions to III-V based PV gives an atomic scale understanding of compositional and dopant profiles across interfaces and tunnel junctions and the initial stages of alloy clustering and dopant accumulation. Details on APT experimental methods and future in-situ instrumentation developments are illustrated.

Gorman, B. P.; Guthrey, H.; Norman, A. G.; Al-Jassim, M.; Lawrence, D.; Prosa, T.

2011-07-01T23:59:59.000Z

274

Waveform Inversion with Source Encoding for Breast Sound Speed Reconstruction in Ultrasound Computed Tomography  

E-Print Network [OSTI]

Ultrasound computed tomography (USCT) holds great promise for improving the detection and management of breast cancer. Because they are based on the acoustic wave equation, waveform inversion-based reconstruction methods can produce images that possess improved spatial resolution properties over those produced by ray-based methods. However, waveform inversion methods are computationally demanding and have not been applied widely in USCT breast imaging. In this work, source encoding concepts are employed to develop an accelerated USCT reconstruction method that circumvents the large computational burden of conventional waveform inversion methods. This method, referred to as the waveform inversion with source encoding (WISE) method, encodes the measurement data using a random encoding vector and determines an estimate of the sound speed distribution by solving a stochastic optimization problem by use of a stochastic gradient descent algorithm. Both computer-simulation and experimental phantom studies are conduc...

Wang, Kun; Anis, Fatima; Li, Cuiping; Duric, Neb; Anastasio, Mark A

2015-01-01T23:59:59.000Z

275

A Fast local Reconstruction algorithm by selective backprojection for Low-Dose in Dental Computed Tomography  

E-Print Network [OSTI]

High radiation dose in computed tomography (CT) scans increases the lifetime risk of cancer, which become a major clinical concern. The backprojection-filtration (BPF) algorithm could reduce radiation dose by reconstructing images from truncated data in a short scan. In dental CT, it could reduce radiation dose for the teeth by using the projection acquired in a short scan, and could avoid irradiation to other part by using truncated projection. However, the limit of integration for backprojection varies per PI-line, resulting in low calculation efficiency and poor parallel performance. Recently, a tent BPF (T-BPF) has been proposed to improve calculation efficiency by rearranging projection. However, the memory-consuming data rebinning process is included. Accordingly, the chose-BPF (C-BPF) algorithm is proposed in this paper. In this algorithm, the derivative of projection is backprojected to the points whose x coordinate is less than that of the source focal spot to obtain the differentiated backprojection...

Bin, Yan; Yu, Han; Feng, Zhang; Chao, Wang Xian; Lei, Li

2013-01-01T23:59:59.000Z

276

Silicon photomultiplier choice for the scintillating fibre tracker in second generation proton computed tomography scanner  

SciTech Connect (OSTI)

Scintillating fibers are capable of charged particle tracking with high position resolution, as demonstrated by the central fiber tracker of the D0 experiment. The charged particles will deposit less energy in the polystyrene scintillating fibers as opposed to a typical silicon tracker of the same thickness, while SiPM's are highly efficient at detecting photons created by the passage of the charged particle through the fibers. The current prototype of the Proton Computed Tomography (pCT) tracker uses groups of three 0.5 mm green polystyrene based scintillating fibers connected to a single SiPM, while first generation prototype tracker used Silicon strip detectors. The results of R&D for the Scintillating Fiber Tracker (SFT) as part of the pCT detector are outlined, and the premise for the selection of SiPM is discussed.

Gearhart, A.; Johnson, E.; Medvedev, V.; /Northern Illinois U.; Ronzhin, A.; /Fermilab; Rykalin, V.; /Northern Illinois U.; Rubinov, P.; /Fermilab; Sleptcov, V.; /Unlisted, RU

2012-03-01T23:59:59.000Z

277

Digital Radiography and Computed Tomography Project -- Fully Integrated Linear Detector ArrayStatus Report  

SciTech Connect (OSTI)

The field-portable Digital Radiography and Computed Tomography (DRCT) x-ray inspection systems developed for the Project Manager for NonStockpile Chemical Materiel (PMNSCM) over the past 13 years have used linear diode detector arrays from two manufacturers; Thomson and Thales. These two manufacturers no longer produce this type of detector. In the interest of insuring the long term viability of the portable DRCT single munitions inspection systems and to improve the imaging capabilities, this project has been investigating improved, commercially available detectors. During FY-10, detectors were evaluated and one in particular, manufactured by Detection Technologies (DT), Inc, was acquired for possible integration into the DRCT systems. The remainder of this report describes the work performed in FY-11 to complete evaluations and fully integrate the detector onto a representative DRCT platform.

Tim Roney; Robert Seifert; Bob Pink; Mike Smith

2011-09-01T23:59:59.000Z

278

NMR tomography of the three-qubit Deutsch-Jozsa algorithm  

SciTech Connect (OSTI)

The optimized version of the Deutsch-Jozsa algorithm proposed by Collins et al. was implemented using the three {sup 19}F nuclear spins of 2,3,4-trifluoroaniline as qubits. To emulate the behavior of pure quantum-mechanical states pseudopure states of the ensemble were prepared prior to execution of the algorithm. Full tomography of the density matrix was employed to obtain detailed information about initial, intermediate, and final states. Information, thus obtained, was applied to optimize the pulse sequences used. It is shown that substantial improvement of the fidelity of the preparation may be achieved by compensating the effects caused by the different relaxation behavior of the different substates of the density matrix. All manipulations of the quantum states were performed under the conditions of unresolved spin-spin interactions.

Mangold, Oliver; Heidebrecht, Andreas; Mehring, Michael [2. Physikalisches Institut, University of Stuttgart, Stuttgart (Germany)

2004-10-01T23:59:59.000Z

279

Using electrokinetic phenomena and electrical resistance tomography to characterize the movement of subsurface fluids  

DOE Patents [OSTI]

This invention relates generally to the remote detections of subsurface liquid contaminants using in combination a geophysical technique known as ERT and an EKS. Electrokinetic transport is used to enhance the ability of electrical resistance tomography (ERT) to detect position and movement of subsurface contaminant liquids, particles or ions. ERT images alone are difficult to interpret because of natural inhomogeneities in soil composition and electrical properties. By subtracting two or more ERT images obtained before and after field induced movement, a high contrast image of a plume of distinct electrokinetic properties can be seen. The invention is applicable to important subsurface characterization problems including, as examples, (1) detection of liquid-saturated plumes of contaminants such as those associated with leaks from underground storage tanks containing hazardous concentrated electrolytes, (2) detection and characterization of soils contaminated with organic pollutants such as droplets of gasoline; and (3) monitoring the progress of electrokinetic containment or clean up of underground contamination.

Ramirez, Abelardo L. (Pleasanton, CA); Cooper, John F. (Oakland, CA); Daily, William D. (Livermore, CA)

1996-01-01T23:59:59.000Z

280

Using electrokinetic phenomena and electrical resistance tomography to characterize the movement of subsurface fluids  

DOE Patents [OSTI]

This invention relates generally to the remote detections of subsurface liquid contaminants using in combination a geophysical technique known as ERT and an EKS. Electrokinetic transport is used to enhance the ability of electrical resistance tomography (ERT) to detect position and movement of subsurface contaminant liquids, particles or ions. ERT images alone are difficult to interpret because of natural inhomogeneities in soil composition and electrical properties. By subtracting two or more ERT images obtained before and after field induced movement, a high contrast image of a plume of distinct electrokinetic properties can be seen. The invention is applicable to important subsurface characterization problems including, as examples, (1) detection of liquid-saturated plumes of contaminants such as those associated with leaks from underground storage tanks containing hazardous concentrated electrolytes, (2) detection and characterization of soils contaminated with organic pollutants such as droplets of gasoline; and (3) monitoring the progress of electrokinetic containment or clean up of underground contamination. 1 fig.

Ramirez, A.L.; Cooper, J.F.; Daily, W.D.

1996-02-27T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium  

DOE Patents [OSTI]

A method and apparatus for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

Beller, Laurence S. (Idaho Falls, ID)

1993-01-01T23:59:59.000Z

282

Markov Random Field Based Automatic Image Alignment for ElectronTomography  

SciTech Connect (OSTI)

Cryo electron tomography (cryo-ET) is the primary method for obtaining 3D reconstructions of intact bacteria, viruses, and complex molecular machines ([7],[2]). It first flash freezes a specimen in a thin layer of ice, and then rotates the ice sheet in a transmission electron microscope (TEM) recording images of different projections through the sample. The resulting images are aligned and then back projected to form the desired 3-D model. The typical resolution of biological electron microscope is on the order of 1 nm per pixel which means that small imprecision in the microscope's stage or lenses can cause large alignment errors. To enable a high precision alignment, biologists add a small number of spherical gold beads to the sample before it is frozen. These beads generate high contrast dots in the image that can be tracked across projections. Each gold bead can be seen as a marker with a fixed location in 3D, which provides the reference points to bring all the images to a common frame as in the classical structure from motion problem. A high accuracy alignment is critical to obtain a high resolution tomogram (usually on the order of 5-15nm resolution). While some methods try to automate the task of tracking markers and aligning the images ([8],[4]), they require user intervention if the SNR of the image becomes too low. Unfortunately, cryogenic electron tomography (or cryo-ET) often has poor SNR, since the samples are relatively thick (for TEM) and the restricted electron dose usually results in projections with SNR under 0 dB. This paper shows that formulating this problem as a most-likely estimation task yields an approach that is able to automatically align with high precision cryo-ET datasets using inference in graphical models. This approach has been packaged into a publicly available software called RAPTOR-Robust Alignment and Projection estimation for Tomographic Reconstruction.

Moussavi, Farshid; Amat, Fernando; Comolli, Luis R.; Elidan, Gal; Downing, Kenneth H.; Horowitz, Mark

2007-11-30T23:59:59.000Z

283

September 15, 2005 14:10 WSPC/Trim Size: 9in x 6in for Review Volume bickel-nair-final-1 NETWORK TOMOGRAPHY  

E-Print Network [OSTI]

. Nair ¡ and Bowei Xi ¢ Statistical Sciences Group Los Alamos National Laboratory Los Alamos, NM 87545), Park and Willinger (2000) and references therein). The work in network tomography has been stimulated

Xi, Bowei

284

Addressing the risks of diagnostic radiology : what should be done about the increasing use of computed tomography in the United States  

E-Print Network [OSTI]

Computed tomography (CT) is a prominent procedure in the US with larger radiation doses than traditional radiology. CT is a powerful tool in the diagnosis of a wide variety of conditions and its use has grown quickly because ...

Eastwick, Gary (Gary A.)

2010-01-01T23:59:59.000Z

285

High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography  

SciTech Connect (OSTI)

We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage needed, and their non-sensitivity to magnetic fields. While investigations into this technique have begun elsewhere, we feel that the extensive SiPM characterization and data acquisition expertise of Fermilab, and the historical in-depth research of PET imaging at University of Chicago will combine to make significant strides in this field. We also benefit by a working relationship with the SiPM producer STMicroelectronics (STM).

Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; /Fermilab; Kim, H.; Chen, C.; Kao, C.; /Chicago U.; Niessen, K.; /SUNY, Buffalo; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

2011-02-01T23:59:59.000Z

286

Fluorodeoxyglucose Positron Emission Tomography Response and Normal Tissue Regeneration After Stereotactic Body Radiotherapy to Liver Metastases  

SciTech Connect (OSTI)

Purpose: To characterize changes in standardized uptake value (SUV) in positron emission tomography (PET) scans and determine the pace of normal tissue regeneration after stereotactic body radiation therapy (SBRT) for solid tumor liver metastases. Methods and Materials: We reviewed records of patients with liver metastases treated with SBRT to {>=}40 Gy in 3-5 fractions. Evaluable patients had pretreatment PET and {>=}1 post-treatment PET. Each PET/CT scan was fused to the planning computed tomography (CT) scan. The maximum SUV (SUV{sub max}) for each lesion and the total liver volume were measured on each PET/CT scan. Maximum SUV levels before and after SBRT were recorded. Results: Twenty-seven patients with 35 treated liver lesions were studied. The median follow-up was 15.7 months (range, 1.5-38.4 mo), with 5 PET scans per patient (range, 2-14). Exponential decay curve fitting (r=0.97) showed that SUV{sub max} declined to a plateau of 3.1 for controlled lesions at 5 months after SBRT. The estimated SUV{sub max} decay half-time was 2.0 months. The SUV{sub max} in controlled lesions fluctuated up to 4.2 during follow-up and later declined; this level is close to 2 standard deviations above the mean normal liver SUV{sub max} (4.01). A failure cutoff of SUV{sub max} {>=}6 is twice the calculated plateau SUV{sub max} of controlled lesions. Parenchymal liver volume decreased by 20% at 3-6 months and regenerated to a new baseline level approximately 10% below the pretreatment level at 12 months. Conclusions: Maximum SUV decreases over the first months after SBRT to plateau at 3.1, similar to the median SUV{sub max} of normal livers. Transient moderate increases in SUV{sub max} may be observed after SBRT. We propose a cutoff SUV{sub max} {>=}6, twice the baseline normal liver SUV{sub max}, to score local failure by PET criteria. Post-SBRT values between 4 and 6 would be suspicious for local tumor persistence or recurrence. The volume of normal liver reached nadir 3-6 months after SBRT and regenerated within the next 6 months.

Stinauer, Michelle A., E-mail: Michelle.Stinauer@ucdenver.edu [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Diot, Quentin; Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)

2012-08-01T23:59:59.000Z

287

Data fusion in X-ray computed tomography using a superiorization approach  

SciTech Connect (OSTI)

X-ray computed tomography (CT) is an important and widespread inspection technique in industrial non-destructive testing. However, large-sized and heavily absorbing objects cause artifacts due to either the lack of penetration of the specimen in specific directions or by having data from only a limited angular range of views. In such cases, valuable information about the specimen is not revealed by the CT measurements alone. Further imaging modalities, such as optical scanning and ultrasonic testing, are able to provide data (such as an edge map) that are complementary to the CT acquisition. In this paper, a superiorization approach (a newly developed method for constrained optimization) is used to incorporate the complementary data into the CT reconstruction; this allows precise localization of edges that are not resolvable from the CT data by itself. Superiorization, as presented in this paper, exploits the fact that the simultaneous algebraic reconstruction technique (SART), often used for CT reconstruction, is resilient to perturbations; i.e., it can be modified to produce an output that is as consistent with the CT measurements as the output of unmodified SART, but is more consistent with the complementary data. The application of this superiorized SART method to measured data of a turbine blade demonstrates a clear improvement in the quality of the reconstructed image.

Schrapp, Michael J. [Siemens AG, CT Munich, Germany and Physics Department E21, Technical University of Munich, Munich (Germany)] [Siemens AG, CT Munich, Germany and Physics Department E21, Technical University of Munich, Munich (Germany); Herman, Gabor T. [Department of Computer Science, The Graduate Center, City University of New York, New York, New York 10016 (United States)] [Department of Computer Science, The Graduate Center, City University of New York, New York, New York 10016 (United States)

2014-05-15T23:59:59.000Z

288

Molecular architecture of axonemal microtubule doublets revealedby cryo-electron tomography  

SciTech Connect (OSTI)

The axoneme, which forms the core of eukaryotic flagella and cilia, is one of the largest macromolecular machines with a structure that is largely conserved from protists to mammals. Microtubule doublets are structural components of axonemes containing a number of proteins besides tubulin, and are usually found in arrays of nine doublets arranged around two singlet microtubules. Coordinated sliding of adjacent doublets, which involves a host of other proteins in the axoneme, produces periodic beating movements of the axoneme. We have obtained a 3D density map of intact microtubule doublets using cryo-electron tomography and image averaging. Our map, with a resolution of about 3 nm, provides insights into locations of particular proteins within the doublets and the structural features of the doublets that define their mechanical properties. We identify likely candidates for several of these non-tubulin components of the doublets. This work offers novel insight on how tubulin protofilaments and accessory proteins attach together to form the doublets and provides a structural basis for understanding doublet function in axonemes.

Sui, Haixin; Downing, Kenneth H.

2006-05-22T23:59:59.000Z

289

MAPPING EARTH ANALOGS FROM PHOTOMETRIC VARIABILITY: SPIN-ORBIT TOMOGRAPHY FOR PLANETS IN INCLINED ORBITS  

SciTech Connect (OSTI)

Aiming at obtaining detailed information on the surface environment of Earth analogs, Kawahara and Fujii proposed an inversion technique of annual scattered light curves named spin-orbit tomography (SOT), which enables us to sketch a two-dimensional albedo map from annual variation of the disk-integrated scattered light, and demonstrated the method with a planet in a face-on orbit. We extend it to be applicable to general geometric configurations, including low-obliquity planets like the Earth in inclined orbits. We simulate light curves of the Earth in an inclined orbit in three photometric bands (0.4-0.5 {mu}m, 0.6-0.7 {mu}m, and 0.8-0.9 {mu}m) and show that the distribution of clouds, snow, and continents is retrieved with the aid of the SOT. We also demonstrate the SOT by applying it to an upright Earth, a tidally locked Earth, and Earth analogs with ancient continental configurations. The inversion is model independent in the sense that we do not assume specific albedo models when mapping the surface, and hence applicable in principle to any kind of inhomogeneity. This method can potentially serve as a unique tool to investigate the exohabitats/exoclimes of Earth analogs.

Fujii, Yuka [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Kawahara, Hajime, E-mail: yuka.fujii@utap.phys.s.u-tokyo.ac.jp [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)

2012-08-20T23:59:59.000Z

290

Determination of the spatial characteristics of an RF electrodeless discharge by the method of emission tomography  

SciTech Connect (OSTI)

The spatial distribution of the density of mercury atoms in the 7{sup 3}S state in a spherical RF electrode-less gas-discharge lamp is reconstructed by the method of emission tomography. The local values of the corresponding emission coefficients, which are proportional to the density of mercury atoms in the 7{sup 3}S state, are determined from integral (over the plasma volume) measurements of the lamp radiation at a wavelength of 546.1 nm with the help of an algorithm based on the maximum entropy method. The results obtained show that, for all of the operating modes under study, the profile of the density of mercury atoms in the 7{sup 3}S state has a minimum in the center of the lamp and a maximum near its wall. At a generator current of 100 mA and cold-spot temperature of 41 deg. C, the density of mercury atoms in the 7{sup 3}S state is observed to drop substantially both in the center of the lamp and near its wall, the density in the center being reduced to almost zero. An explanation of this phenomenon is proposed.

Denisova, N. V. [Russian Academy of Sciences, Institute of Theoretical and Applied Mechanics, Siberian Division (Russian Federation); Revalde, G.; Skudra, A. [University of Latvia, Institute of Atomic physics and Spectroscopy (Latvia)

2006-11-15T23:59:59.000Z

291

Relationship of brain imaging with radionuclides and with x-ray computed tomography  

SciTech Connect (OSTI)

Because of high sensitivity and specificity for altered local cerebral structure, x-ray computed tomography (CT) is the preferred initial diagnostic imaging study under most circumstances when cerebral disease is suspected. CT has no competitor for detecting fresh intracerebral hemorrhage. Radionuclide imaging (RN) scan is preferred when relative perfusion is to be assessed, in patients allergic to contrast media, and when an adequate CT study is not technically possible. (RN) plays an important complementary role to CT, especially for patients suspected of subacute or chronic subdura hematoma, cerebral infarction, arteriovenous malformations, meningitis, encephalitis, normal pressure hydrocephalus, or when CT findings are inconclusive. When CT is not available, RN serves as a good screening study for suspected cerebral tumor, infection, recent infarction, arteriovenous malformation, and chronic subdural hematoma. Future improvement in radionuclide imaging by means of emission composition potential. The compound plating approacl threshold for all the investigated transistors and fast neutron spectra lies within the raal. The value of the potential slightly changes with the coordinate change in this region, i.e. the charge on a collecting electrode is not practically guided up to a certain moment of time during the movement of nonequilibrium carriers.

Kuhl, D.E.

1981-03-03T23:59:59.000Z

292

Geometric classification of open-cell metal foams using X-ray micro-computed tomography  

SciTech Connect (OSTI)

The geometry of foams has long been an area of interest, and a number of idealized geometric descriptions have been proposed. In order to acquire detailed, quantitative, geometric data for aluminum open-cell metal foams, X-ray {mu}CT is employed. The X-ray {mu}CT images are analyzed using specialized software, FoamView Registered-Sign , from which geometric information including strut length and pore shapes are extracted. The X-ray {mu}CT analysis allows comparison of the ideal geometric models to the actual geometric characteristics of the metal foam samples. The results reveal a high variability in ligament length, as well as features supporting the ideal geometry known as the Weaire-Phelan unit cell. The geometric findings provide information useful for improving current models of open-cell metal foam. Applications can range from predicting heat transfer or load failure to predicting liquid retention. Highlights: Black-Right-Pointing-Pointer Aluminum open-cell metal foams are geometrically classified Black-Right-Pointing-Pointer X-ray micro-computed tomography and specialized software are used to gather geometric data Black-Right-Pointing-Pointer The foams are shown to have a high variability in strut length Black-Right-Pointing-Pointer The Weaire-Phelan unit cell is shown to be a better representative of these foams.

Bock, Jessica, E-mail: bock6@illinois.edu; Jacobi, Anthony M., E-mail: a-jacobi@illinois.edu

2013-01-15T23:59:59.000Z

293

3D Jet Tomography of Twisted Strongly Coupled Quark Gluon Plasmas  

E-Print Network [OSTI]

The triangular enhancement of the rapidity distribution of hadrons produced in p+A reactions relative to p+p is a leading order in A^{1/3}/log(s) violation of longitudinal boost invariance at high energies. In A+A reactions this leads to a trapezoidal enhancement of the local rapidity density of produced gluons. The local rapidity gradient is proportional to the local participant number asymmetry, and leads to an effective rotation in the reaction plane. We propose that three dimensional jet tomography, correlating the long range rapidity and azimuthal dependences of the nuclear modification factor, R_{AA}(\\eta,\\phi,p_\\perp; b>0), can be used to look for this intrinsic longitudinal boost violating structure of $A+A$ collisions to image the produced twisted strongly coupled quark gluon plasma (sQGP). In addition to dipole and elliptic azimuthal moments of R_{AA}, a significant high p_\\perp octupole moment is predicted away from midrapidity. The azimuthal angles of maximal opacity and hence minima of R_{AA} are rotated away from the normal to the reaction plane by an `Octupole Twist' angle, \\theta_3(\\eta), at forward rapidities.

A. Adil; M. Gyulassy

2005-05-01T23:59:59.000Z

294

Combined 3D PET and Optical Projection Tomography Techniques for Plant Root Phenotyping  

E-Print Network [OSTI]

New imaging techniques are in great demand for investigating underground plant roots systems which play an important role in crop production. Compared with other non-destructive imaging modalities, PET can image plant roots in natural soil and produce dynamic 3D functional images which reveal the temporal dynamics of plant-environment interactions. In this study, we combined PET with optical projection tomography (OPT) to evaluate its potential for plant root phenotyping. We used a dedicated high resolution plant PET imager that has a 14 cm transaxial and 10 cm axial field of views, and multi-bed imaging capability. The image resolution is around 1.25 mm using ML-EM reconstruction algorithm. B73 inbred maize seeds were germinated and then grown in a sealed jar with transparent gel-based media. PET scanning started on the day when the first green leaf appeared, and was carried out once a day for 5 days. Each morning, around 10 mCi of 11CO2 was administrated into a custom built plant labeling chamber. After 10 ...

Wang, Qiang; Mathews, Aswin J; Li, Ke; Topp, Christopher; O'Sullivan, Joseph A; Tai, Yuan-Chuan

2015-01-01T23:59:59.000Z

295

Dynamic Inversion for Hydrological Process Monitoring with Electrical Resistance Tomography Under Model Uncertainty  

SciTech Connect (OSTI)

We propose an approach for imaging the dynamics of complex hydrological processes. The evolution of electrically conductive fluids in porous media is imaged using time-lapse electrical resistance tomography. The related dynamic inversion problem is solved using Bayesian filtering techniques, that is, it is formulated as a sequential state estimation problem in which the target is an evolving posterior probability density of the system state. The dynamical inversion framework is based on the state space representation of the system, which involves the construction of a stochastic evolution model and an observation model. The observation model used in this paper consists of the complete electrode model for ERT, with Archie's law relating saturations to electrical conductivity. The evolution model is an approximate model for simulating flow through partially saturated porous media. Unavoidable modeling and approximation errors in both the observation and evolution models are considered by computing approximate statistics for these errors. These models are then included in the construction of the posterior probability density of the estimated system state. This approximation error method allows the use of approximate - and therefore computationally efficient - observation and evolution models in the Bayesian filtering. We consider a synthetic example and show that the incorporation of an explicit model for the model uncertainties in the state space representation can yield better estimates than a frame-by-frame imaging approach.

Lehikoinen, A.; Huttunen, J.M.J.; Finsterle, S.; Kowalsky, M.B.; Kaipio, J.P.

2009-08-01T23:59:59.000Z

296

Atom Probe Tomography Examination of Carbon Redistribution in Quenched and Tempered 4340 Steel  

SciTech Connect (OSTI)

Quenching and tempering produces a wide range of mechanical properties in medium carbon, low alloyed steels - Study fragmentation behavior as a function of heat-treatment. Subtle microstructural changes accompany the mechanical property changes that result from quenching and tempering - Characterize the location and distribution of carbon and alloying elements in the microstructure using atom probe tomography (APT). Perform complementary transmission electron microscopy (TEM). Tempering influences the mechanical properties and fragmentation of quenched 4340 (hemi-shaped samples). APT revealed carbon-enriched features that contain a maximum of {approx}12-14 at.% carbon after quenching to RT (the level of carbon is perhaps associated with the extent of autotempering). TEM confirmed the presence of twinned martensite and indicates {var_epsilon} ({eta}) transition carbides after oil quenching to RT. Tempering at 325 C resulted in carbon-enriched plates (> 25 at.% C) with no significant element partitioning (transition carbides?). Tempering at 450 C and 575 C resulted in cementite ({approx} 25 at.% C) during late stage tempering; Cr, Mn, Mo partitioned to cementite and Si partitioned to ferrite. Tempering at 575 C resulted in P segregation at cementite interfaces and the formation of Cottrell atmospheres.

Clarke, Amy J. [Los Alamos National Laboratory; Miller, Michael K. [ORNL; Alexander, David J. [Los Alamos National Laboratory; Field, Robert D. [Los Alamos National Laboratory; Clarke, Kester D. [Los Alamos National Laboratory

2012-08-07T23:59:59.000Z

297

Low background high efficiency radiocesium detection system based on positron emission tomography technology  

SciTech Connect (OSTI)

After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because {sup 134}Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as {sup 40}K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi{sub 4}Ge{sub 3}O{sub 12} (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from {sup 134}Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

Yamamoto, Seiichi; Ogata, Yoshimune [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)] [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)

2013-09-15T23:59:59.000Z

298

Three-dimensional flow contrast imaging of deep tissue using noncontact diffuse correlation tomography  

SciTech Connect (OSTI)

This study extended our recently developed noncontact diffuse correlation spectroscopy flowmetry system into noncontact diffuse correlation tomography (ncDCT) for three-dimensional (3-D) flow imaging of deep tissue. A linear array of 15 photodetectors and two laser sources connected to a mobile lens-focusing system enabled automatic and noncontact scanning of flow in a region of interest. These boundary measurements were combined with a finite element framework for DCT image reconstruction implemented into an existing software package. This technique was tested in computer simulations and using a tissue-like phantom with anomaly flow contrast design. The cylindrical tube-shaped anomaly was clearly reconstructed in both simulation and phantom. Recovered and assigned flow contrast changes in anomaly were found to be highly correlated: regression slope?=?1.00, R{sup 2}?=?1.00, and p?

Lin, Yu; Huang, Chong; Irwin, Daniel; He, Lian; Shang, Yu; Yu, Guoqiang, E-mail: guoqiang.yu@uky.edu [Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States)

2014-03-24T23:59:59.000Z

299

X-Ray Energy Responses of Silicon Tomography Detectors Irradiated with Fusion Produced Neutrons  

SciTech Connect (OSTI)

In order to clarify the effects of fusion-produced neutron irradiation on silicon semiconductor x-ray detectors, the x-ray energy responses of both n- and p-type silicon tomography detectors used in the Joint European Torus (JET) tokamak (n-type) and the GAMMA 10 tandem mirror (p-type) are studied using synchrotron radiation at the Photon Factory of the National Laboratory for High Energy Accelerator Research Organization (KEK). The fusion neutronics source (FNS) of Japan Atomic Energy Research Institute (JAERI) is employed as well-calibrated D-T neutron source with fluences from 10{sup 13} to 10{sup 15} neutrons/cm{sup 2} onto these semiconductor detectors. Different fluence dependence is found between these two types of detectors; that is, (i) for the n-type detector, the recovery of the degraded response is found after the neutron exposure beyond around 10{sup 13} neutrons/cm{sup 2} onto the detector. A further finding is followed as a 're-degradation' by a neutron irradiation level over about 10{sup 14} neutrons/cm{sup 2}. On the other hand, (ii) the energy response of the p-type detector shows only a gradual decrease with increasing neutron fluences. These properties are interpreted by our proposed theory on semiconductor x-ray responses in terms of the effects of neutrons on the effective doping concentration and the diffusion length of a semiconductor detector.

Kohagura, J. [Plasma Research Centre, University of Tsukuba (Japan); Cho, T. [Plasma Research Centre, University of Tsukuba (Japan); Hirata, M. [Plasma Research Centre, University of Tsukuba (Japan); Numakura, T. [Plasma Research Centre, University of Tsukuba (Japan); Yokoyama, N. [Plasma Research Centre, University of Tsukuba (Japan); Fukai, T. [Plasma Research Centre, University of Tsukuba (Japan); Tomii, Y. [Plasma Research Centre, University of Tsukuba (Japan); Tokioka, S. [Plasma Research Centre, University of Tsukuba (Japan); Miyake, Y. [Plasma Research Centre, University of Tsukuba (Japan); Kiminami, S. [Plasma Research Centre, University of Tsukuba (Japan); Shimizu, K. [Plasma Research Centre, University of Tsukuba (Japan); Miyoshi, S. [Plasma Research Centre, University of Tsukuba (Japan); Hirano, K. [High Energy Accelerator Research Organization (Japan); Yoshida, M. [Japan Atomic Energy Research Institute (Japan); Yamauchi, M. [Japan Atomic Energy Research Institute (Japan); Kondoh, T. [Japan Atomic Energy Research Institute (Japan); Nishitani, T. [Japan Atomic Energy Research Institute (Japan)

2005-01-15T23:59:59.000Z

300

Bayesian soft X-ray tomography using non-stationary Gaussian Processes  

SciTech Connect (OSTI)

In this study, a Bayesian based non-stationary Gaussian Process (GP) method for the inference of soft X-ray emissivity distribution along with its associated uncertainties has been developed. For the investigation of equilibrium condition and fast magnetohydrodynamic behaviors in nuclear fusion plasmas, it is of importance to infer, especially in the plasma center, spatially resolved soft X-ray profiles from a limited number of noisy line integral measurements. For this ill-posed inversion problem, Bayesian probability theory can provide a posterior probability distribution over all possible solutions under given model assumptions. Specifically, the use of a non-stationary GP to model the emission allows the model to adapt to the varying length scales of the underlying diffusion process. In contrast to other conventional methods, the prior regularization is realized in a probability form which enhances the capability of uncertainty analysis, in consequence, scientists who concern the reliability of their results will benefit from it. Under the assumption of normally distributed noise, the posterior distribution evaluated at a discrete number of points becomes a multivariate normal distribution whose mean and covariance are analytically available, making inversions and calculation of uncertainty fast. Additionally, the hyper-parameters embedded in the model assumption can be optimized through a Bayesian Occam's Razor formalism and thereby automatically adjust the model complexity. This method is shown to produce convincing reconstructions and good agreements with independently calculated results from the Maximum Entropy and Equilibrium-Based Iterative Tomography Algorithm methods.

Li, Dong; Svensson, J.; Thomsen, H.; Werner, A.; Wolf, R. [Max Planck Institute for Plasma Physics, Teilinstitut, D-17491 Greifswald (Germany)] [Max Planck Institute for Plasma Physics, Teilinstitut, D-17491 Greifswald (Germany); Medina, F. [Asociación EURATOM-CIEMAT, Madrid (Spain)] [Asociación EURATOM-CIEMAT, Madrid (Spain)

2013-08-15T23:59:59.000Z

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301

Cone beam x-ray luminescence computed tomography: A feasibility study  

SciTech Connect (OSTI)

Purpose: The appearance of x-ray luminescence computed tomography (XLCT) opens new possibilities to perform molecular imaging by x ray. In the previous XLCT system, the sample was irradiated by a sequence of narrow x-ray beams and the x-ray luminescence was measured by a highly sensitive charge coupled device (CCD) camera. This resulted in a relatively long sampling time and relatively low utilization of the x-ray beam. In this paper, a novel cone beam x-ray luminescence computed tomography strategy is proposed, which can fully utilize the x-ray dose and shorten the scanning time. The imaging model and reconstruction method are described. The validity of the imaging strategy has been studied in this paper. Methods: In the cone beam XLCT system, the cone beam x ray was adopted to illuminate the sample and a highly sensitive CCD camera was utilized to acquire luminescent photons emitted from the sample. Photons scattering in biological tissues makes it an ill-posed problem to reconstruct the 3D distribution of the x-ray luminescent sample in the cone beam XLCT. In order to overcome this issue, the authors used the diffusion approximation model to describe the photon propagation in tissues, and employed the sparse regularization method for reconstruction. An incomplete variables truncated conjugate gradient method and permissible region strategy were used for reconstruction. Meanwhile, traditional x-ray CT imaging could also be performed in this system. The x-ray attenuation effect has been considered in their imaging model, which is helpful in improving the reconstruction accuracy. Results: First, simulation experiments with cylinder phantoms were carried out to illustrate the validity of the proposed compensated method. The experimental results showed that the location error of the compensated algorithm was smaller than that of the uncompensated method. The permissible region strategy was applied and reduced the reconstruction error to less than 2 mm. The robustness and stability were then evaluated from different view numbers, different regularization parameters, different measurement noise levels, and optical parameters mismatch. The reconstruction results showed that the settings had a small effect on the reconstruction. The nonhomogeneous phantom simulation was also carried out to simulate a more complex experimental situation and evaluated their proposed method. Second, the physical cylinder phantom experiments further showed similar results in their prototype XLCT system. With the discussion of the above experiments, it was shown that the proposed method is feasible to the general case and actual experiments. Conclusions: Utilizing numerical simulation and physical experiments, the authors demonstrated the validity of the new cone beam XLCT method. Furthermore, compared with the previous narrow beam XLCT, the cone beam XLCT could more fully utilize the x-ray dose and the scanning time would be shortened greatly. The study of both simulation experiments and physical phantom experiments indicated that the proposed method was feasible to the general case and actual experiments.

Chen Dongmei; Zhu Shouping; Yi Huangjian; Zhang Xianghan; Chen Duofang; Liang Jimin [School of Life Sciences and Technology, Xidian University, Xi'an 710071 (China); Tian Jie [School of Life Sciences and Technology, Xidian University, Xi'an 710071 (China); Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, Beijing 100190 (China)

2013-03-15T23:59:59.000Z

302

Cone-beam Computed Tomography-guided Stereotactic Liver Punctures: A Phantom Study  

SciTech Connect (OSTI)

Purpose: Images from computed tomography (CT), combined with navigation systems, improve the outcomes of local thermal therapies that are dependent on accurate probe placement. Although the usage of CT is desired, its availability for time-consuming radiological interventions is limited. Alternatively, three-dimensional images from C-arm cone-beam CT (CBCT) can be used. The goal of this study was to evaluate the accuracy of navigated CBCT-guided needle punctures, controlled with CT scans. Methods: Five series of five navigated punctures were performed on a nonrigid phantom using a liver specific navigation system and CBCT volumetric dataset for planning and navigation. To mimic targets, five titanium screws were fixed to the phantom. Target positioning accuracy (TPE{sub CBCT}) was computed from control CT scans and divided into lateral and longitudinal components. Additionally, CBCT-CT guidance accuracy was deducted by performing CBCT-to-CT image coregistration and measuring TPE{sub CBCT-CT} from fused datasets. Image coregistration was evaluated using fiducial registration error (FRE{sub CBCT-CT}) and target registration error (TRE{sub CBCT-CT}). Results: Positioning accuracies in lateral directions pertaining to CBCT (TPE{sub CBCT} = 2.1 {+-} 1.0 mm) were found to be better to those achieved from previous study using CT (TPE{sub CT} = 2.3 {+-} 1.3 mm). Image coregistration error was 0.3 {+-} 0.1 mm, resulting in an average TRE of 2.1 {+-} 0.7 mm (N = 5 targets) and average Euclidean TPE{sub CBCT-CT} of 3.1 {+-} 1.3 mm. Conclusions: Stereotactic needle punctures might be planned and performed on volumetric CBCT images and controlled with multidetector CT with positioning accuracy higher or similar to those performed using CT scanners.

Toporek, Grzegorz, E-mail: grzegorz.toporek@artorg.unibe.ch; Wallach, Daphne, E-mail: daphne.wallach@artorg.unibe.ch; Weber, Stefan [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland)] [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland); Bale, Reto; Widmann, Gerlig [Innsbruck Medical University, Section of Microinvasive Therapy, Department of Radiology (Austria)] [Innsbruck Medical University, Section of Microinvasive Therapy, Department of Radiology (Austria)

2013-12-15T23:59:59.000Z

303

Efficacy of Lower-Body Shielding in Computed Tomography Fluoroscopy-Guided Interventions  

SciTech Connect (OSTI)

Purpose: Computed tomography (CT) fluoroscopy-guided interventions pose relevant radiation exposure to the interventionalist. The goal of this study was to analyze the efficacy of lower-body shielding as a simple structural method for decreasing radiation dose to the interventionalist without limiting access to the patient. Material and Methods: All examinations were performed with a 128-slice dual source CT scanner (12 Multiplication-Sign 1.2-mm collimation; 120 kV; and 20, 40, 60, and 80 mAs) and an Alderson-Rando phantom. Scatter radiation was measured with an ionization chamber and a digital dosimeter at standardized positions and heights with and without a lower-body lead shield (0.5-mm lead equivalent; Kenex, Harlow, UK). Dose decreases were computed for the different points of measurement. Results: On average, lower-body shielding decreased scatter radiation by 38.2% within a 150-cm radius around the shielding. This decrease is most significant close to the gantry opening and at low heights of 50 and 100 cm above the floor with a maximum decrease of scatter radiation of 95.9% close to the scanner's isocentre. With increasing distance to the gantry opening, the effect decreased. There is almost no dose decrease effect at {>=}150 above the floor. Scatter radiation and its decrease were linearly correlated with the tube current-time product (r{sup 2} = 0.99), whereas percent scatter radiation decrease was independent of the tube current-time product. Conclusion: Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.

Mahnken, Andreas H., E-mail: mahnken@rad.rwth-aachen.de [RWTH Aachen, Department of Diagnostic and Interventional Radiology (Germany); Sedlmair, Martin [Siemens, Healthcare Sector (Germany); Ritter, Christine [University of Copenhagen, Niels Bohr Institute (Denmark); Banckwitz, Rosemarie; Flohr, Thomas [Siemens, Healthcare Sector (Germany)

2012-12-15T23:59:59.000Z

304

Adaptive Radiotherapy for Prostate Cancer Using Kilovoltage Cone-Beam Computed Tomography: First Clinical Results  

SciTech Connect (OSTI)

Purpose: To evaluate the first clinical results of an off-line adaptive radiotherapy (ART) protocol for prostate cancer using kilovoltage cone-beam computed tomography (CBCT) in combination with a diet and mild laxatives. Methods and Materials: Twenty-three patients began treatment with a planning target volume (PTV) margin of 10 mm. The CBCT scans acquired during the first six fractions were used to generate an average prostate clinical target volume (AV-CTV), and average rectum (AV-Rect). Using these structures, a new treatment plan was generated with a 7-mm PTV margin. Weekly CBCT scans were used to monitor the CTV coverage. A diet and mild laxatives were introduced to improve image quality and reduce prostate motion. Results: Twenty patients were treated with conform ART protocol. For these patients, 91% of the CBCT scans could be used to calculate the AV-CTV and AV-Rect. In 96% of the follow-up CBCT scans, the CTV was located within the average PTV. In the remaining 4%, the prostate extended the PTV by a maximum of 1 mm. Systematic and random errors for organ motion were reduced by a factor of two compared with historical data without diet and laxatives. An average PTV reduction of 29% was achieved. The volume of the AV-Rect that received >65 Gy was reduced by 19%. The mean dose to the anal wall was reduced on average by 4.8 Gy. Conclusions: We safely reduced the high-dose region by 29%. The reduction in irradiated volume led to a significant reduction in the dose to the rectum. The diet and laxatives improved the image quality and tended to reduce prostate motion.

Nijkamp, Jasper [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Pos, Floris J. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)], E-mail: f.pos@nki.nl; Nuver, Tonnis T.; Jong, Rianne de; Remeijer, Peter; Sonke, Jan-Jakob; Lebesque, Joos V. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

2008-01-01T23:59:59.000Z

305

Demonstration of Emitted-Neutron Computed Tomography to Count Fuel Pins  

SciTech Connect (OSTI)

In this paper, we report demonstration of emitted-neutron computed tomography using fast fission neutrons to infer the geometry of sources of special nuclear material (SNM) such as fuel pins. In a proof-of-concept measurement at the Idaho National Laboratory s (INL s) Zero Power Physics Reactor (ZPPR) facility, an array of unirradiated Pu MOX fuel rodlets in a soup can were imaged, and a bias defect consisting of a single rodlet containing Pu replaced by one containing depleted uranium (DU) was detected. The imaging system employed in the demonstration is based on a newly constructed array of pixelated neutron detectors that are suitable for arrangement in a close-packed imaging array and whose active volume consists of liquid scintillator EJ-309 which allows neutron-gamma discrimination via pulse shape to enable pure fast-neutron imaging. The imaging array was used along with a radial collimator aperture in order to perform high quality fast-neutron imaging where tomographic reconstruction of slices through an object resolve neutron sources similar in dimension to a fuel pellet, or about 1 cm. Measurements were performed at Oak Ridge National Laboratory (ORNL) with neutron sources in addition to those performed at the INL s ZPPR facility with Pu MOX fuel rodlets. An analogous capability to detect single-pin defects in spent fuel assemblies would be desirable, such as for safeguards verification measurements of spent fuel assemblies just prior to transferring them from the spent fuel cooling pool to long term dry cask storage. This paper describes the design and construction of the present imager, characterization measurements with neutron sources at ORNL, measurements with SNM at INL s ZPPR facility, and feasibility of building an analogous imager for spent fuel measurements.

Hausladen, Paul [ORNL] [ORNL; Blackston, Matthew A [ORNL] [ORNL; Brubaker, E. [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Chichester, David [Idaho National Laboratory (INL)] [Idaho National Laboratory (INL); Marleau, P. [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Newby, Robert Jason [ORNL] [ORNL

2012-01-01T23:59:59.000Z

306

Demonstration of Emitted-Neutron Computed Tomography to Count Fuel Pins  

SciTech Connect (OSTI)

In this paper, we report demonstration of emitted-neutron computed tomography using fast fission neutrons to infer the geometry of sources of special nuclear material (SNM) such as fuel pins. In a proof-of-concept measurement at the Idaho National Laboratory’s (INL’s) Zero Power Physics Reactor (ZPPR) facility, an array of unirradiated Pu MOX fuel rodlets in a soup can were imaged, and a bias defect consisting of a single rodlet containing Pu replaced by one containing depleted uranium (DU) was detected. The imaging system employed in the demonstration is based on a newly constructed array of pixelated neutron detectors that are suitable for arrangement in a close-packed imaging array and whose active volume consists of liquid scintillator EJ-309 which allows neutron-gamma discrimination via pulse shape to enable pure fast-neutron imaging. The imaging array was used along with a radial collimator aperture in order to perform high quality fast-neutron imaging where tomographic reconstruction of slices through an object resolve neutron sources similar in dimension to a fuel pellet, or about 1 cm. Measurements were performed at Oak Ridge National Laboratory (ORNL) with neutron sources in addition to those performed at the INL’s ZPPR facility with Pu MOX fuel rodlets. An analogous capability to detect single-pin defects in spent fuel assemblies would be desirable, such as for safeguards verification measurements of spent fuel assemblies just prior to transferring them from the spent fuel cooling pool to long term dry cask storage. This paper describes the design and construction of the present imager, characterization measurements with neutron sources at ORNL, measurements with SNM at INL’s ZPPR facility, and feasibility of building an analogous imager for spent fuel measurements.

P. A. Hausladen; M. A. Blackston; E. Brubaker; D. L. Chichester; P. Marleau; R. J. Newby

2012-07-01T23:59:59.000Z

307

2-D Coda and Direct Wave Attenuation Tomography in Northern Italy  

SciTech Connect (OSTI)

A 1-D coda method was proposed by Mayeda et al. (2003) in order to obtain stable seismic source moment-rate spectra using narrowband coda envelope measurements. That study took advantage of the averaging nature of coda waves to derive stable amplitude measurements taking into account all propagation, site, and Sto-coda transfer function effects. Recently this methodology was applied to micro earthquake data sets from three sub-regions of northern Italy (i.e., western Alps, northern Apennines and eastern Alps). Since the study regions were small, ranging between local-to-near-regional distances, the simple 1-D path assumptions used in the coda method worked very well. The lateral complexity of this region would suggest, however, that a 2-D path correction might provide even better results if the datasets were combined, especially when paths traverse larger distances and complicated regions. The structural heterogeneity of northern Italy makes the region ideal to test the extent to which coda variance can be reduced further by using a 2-D Q tomography technique. The approach we use has been developed by Phillips et al. (2005) and is an extension of previous amplitude ratio techniques to remove source effects from the inversion. The method requires some assumptions such as isotropic source radiation which is generally true for coda waves. Our results are compared against direct Swave inversions for 1/Q and results from both share very similar attenuation features that coincide with known geologic structures. We compare our results with those derived from direct waves as well as some recent results from northern California obtained by Mayeda et al. (2005) which tested the same tomographic methodology applied in this study to invert for 1/Q. We find that 2-D coda path corrections for this region significantly improve upon the 1-D corrections, in contrast to California where only a marginal improvement was observed. We attribute this difference to stronger lateral variations in Q for northern Italy relative to California.

Morasca, P; Mayeda, K; Gok, R; Phillips, W S; Malagnini, L

2007-10-17T23:59:59.000Z

308

Positron Emission Tomography (PET) Evaluation After Initial Chemotherapy and Radiation Therapy Predicts Local Control in Rhabdomyosarcoma  

SciTech Connect (OSTI)

Purpose: 18-fluorodeoxyglucose positron emission tomography (PET) is already an integral part of staging in rhabdomyosarcoma. We investigated whether primary-site treatment response characterized by serial PET imaging at specific time points can be correlated with local control. Patients and Methods: We retrospectively examined 94 patients with rhabdomyosarcoma who received initial chemotherapy 15 weeks (median) before radiotherapy and underwent baseline, preradiation, and postradiation PET. Baseline PET standardized uptake values (SUVmax) and the presence or absence of abnormal uptake (termed PET-positive or PET-negative) both before and after radiation were examined for the primary site. Local relapse-free survival (LRFS) was calculated according to baseline SUVmax, PET-positive status, and PET-negative status by the Kaplan-Meier method, and comparisons were tested with the log-rank test. Results: The median patient age was 11 years. With 3-year median follow-up, LRFS was improved among postradiation PET-negative vs PET-positive patients: 94% vs 75%, P=.02. By contrast, on baseline PET, LRFS was not significantly different for primary-site SUVmax {<=}7 vs >7 (median), although the findings suggested a trend toward improved LRFS: 96% for SUVmax {<=}7 vs 79% for SUVmax >7, P=.08. Preradiation PET also suggested a statistically insignificant trend toward improved LRFS for PET-negative (97%) vs PET-positive (81%) patients (P=.06). Conclusion: Negative postradiation PET predicted improved LRFS. Notably, 77% of patients with persistent postradiation uptake did not experience local failure, suggesting that these patients could be closely followed up rather than immediately referred for intervention. Negative baseline and preradiation PET findings suggested statistically insignificant trends toward improved LRFS. Additional study may further understanding of relationships between PET findings at these time points and outcome in rhabdomyosarcoma.

Dharmarajan, Kavita V., E-mail: dharmark@mskcc.org [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States); Wexler, Leonard H.; Gavane, Somali; Fox, Josef J.; Schoder, Heiko; Tom, Ashlyn K.; Price, Alison N.; Meyers, Paul A.; Wolden, Suzanne L. [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States)] [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States)

2012-11-15T23:59:59.000Z

309

Experimental Investigation of Material Flows Within FSWs Using 3D Tomography  

SciTech Connect (OSTI)

There exists significant prior work using tracers or pre-placed hardened markers within friction stir welding (FSWing) to experimentally explore material flow within the FSW process. Our experiments replaced markers with a thin sheet of copper foil placed between the 6061 aluminum lap and butt joints that were then welded. The absorption characteristics of x-rays for copper and aluminum are significantly different allowing for non-destructive evaluation (NDE) methods such as x-ray computed tomography (CT) to be used to demonstrate the material movement within the weldment on a much larger scale than previously shown. 3D CT reconstruction of the copper components of the weldment allows for a unique view into the final turbulent state of the welding process as process parameters are varied. The x-ray CT data of a section of the weld region was collected using a cone-beam x-ray imaging system developed at the INL. Six-hundred projections were collected over 360-degrees using a 160-kVp Bremsstrahlung x-ray generator (25-micrometer focal spot) and amorphoussilicon x-ray detector. The region of the object that was imaged was about 3cm tall and 1.5cm x 1cm in cross section, and was imaged at a magnification of about 3.6x. The data were reconstructed on a 0.5x0.5x0.5 mm3 voxel grid. After reconstruction, the aluminum and copper could be easily discriminated using a gray level threshold allowing visualization of the copper components. Fractal analysis of the tomographic reconstructed material topology is investigated as a means to quantify macro level material flow based on process parameters. The results of multi-pass FSWs show increased refinement of the copper trace material. Implications of these techniques for quantifying process flow are discussed.

Charles R. Tolle; Timothy A. White; Karen S. Miller; Denis E. Clark; Herschel B. Smartt

2008-06-01T23:59:59.000Z

310

PILOT-SCALE FIELD VALIDATION OF THE LONG ELECTRODE ELECTRICAL RESISTIVITY TOMOGRAPHY METHOD  

SciTech Connect (OSTI)

Field validation for the long electrode electrical resistivity tomography (LE-ERT) method was attempted in order to demonstrate the performance of the technique in imaging a simple buried target. The experiment was an approximately 1/17 scale mock-up of a region encompassing a buried nuclear waste tank on the Hanford site. The target of focus was constructed by manually forming a simulated plume within the vadose zone using a tank waste simulant. The LE-ERT results were compared to ERT using conventional point electrodes on the surface and buried within the survey domain. Using a pole-pole array, both point and long electrode imaging techniques identified the lateral extents of the pre-formed plume with reasonable fidelity, but the LE-ERT was handicapped in reconstructing the vertical boundaries. The pole-dipole and dipole-dipole arrays were also tested with the LE-ERT method and were shown to have the least favorable target properties, including the position of the reconstructed plume relative to the known plume and the intensity of false positive targets. The poor performance of the pole-dipole and dipole-dipole arrays was attributed to an inexhaustive and non-optimal coverage of data at key electrodes, as well as an increased noise for electrode combinations with high geometric factors. However, when comparing the model resolution matrix among the different acquisition strategies, the pole-dipole and dipole-dipole arrays using long electrodes were shown to have significantly higher average and maximum values than any pole-pole array. The model resolution describes how well the inversion model resolves the subsurface. Given the model resolution performance of the pole-dipole and dipole-dipole arrays, it may be worth investing in tools to understand the optimum subset of randomly distributed electrode pairs to produce maximum performance from the inversion model.

GLASER DR; RUCKER DF; CROOK N; LOKE MH

2011-07-14T23:59:59.000Z

311

Respiratory triggered 4D cone-beam computed tomography: A novel method to reduce imaging dose  

SciTech Connect (OSTI)

Purpose: A novel method called respiratory triggered 4D cone-beam computed tomography (RT 4D CBCT) is described whereby imaging dose can be reduced without degrading image quality. RT 4D CBCT utilizes a respiratory signal to trigger projections such that only a single projection is assigned to a given respiratory bin for each breathing cycle. In contrast, commercial 4D CBCT does not actively use the respiratory signal to minimize image dose. Methods: To compare RT 4D CBCT with conventional 4D CBCT, 3600 CBCT projections of a thorax phantom were gathered and reconstructed to generate a ground truth CBCT dataset. Simulation pairs of conventional 4D CBCT acquisitions and RT 4D CBCT acquisitions were developed assuming a sinusoidal respiratory signal which governs the selection of projections from the pool of 3600 original projections. The RT 4D CBCT acquisition triggers a single projection when the respiratory signal enters a desired acquisition bin; the conventional acquisition does not use a respiratory trigger and projections are acquired at a constant frequency. Acquisition parameters studied were breathing period, acquisition time, and imager frequency. The performance of RT 4D CBCT using phase based and displacement based sorting was also studied. Image quality was quantified by calculating difference images of the test dataset from the ground truth dataset. Imaging dose was calculated by counting projections. Results: Using phase based sorting RT 4D CBCT results in 47% less imaging dose on average compared to conventional 4D CBCT. Image quality differences were less than 4% at worst. Using displacement based sorting RT 4D CBCT results in 57% less imaging dose on average, than conventional 4D CBCT methods; however, image quality was 26% worse with RT 4D CBCT. Conclusions: Simulation studies have shown that RT 4D CBCT reduces imaging dose while maintaining comparable image quality for phase based 4D CBCT; image quality is degraded for displacement based RT 4D CBCT in its current implementation.

Cooper, Benjamin J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006, Australia and Department of Medical Physics and Radiation Engineering, Canberra Hospital, Canberra, ACT 2605 (Australia); O'Brien, Ricky T.; Keall, Paul J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006 (Australia); Balik, Salim; Hugo, Geoffrey D. [Radiation Oncology, Virginia Commonwealth University, 401 College Street, P.O.Box 980058, Richmond, Virginia 23298-0058 (United States)

2013-04-15T23:59:59.000Z

312

Design of Mega-Voltage X-ray Digital Radiography and Computed Tomography Performance Phantoms  

SciTech Connect (OSTI)

A number of fundamental scientific questions have arisen concerning the operation of high-energy DR and CT systems. Some of these questions include: (1) How deeply can such systems penetrate thickly shielded objects? (2) How well can such systems distinguish between dense and relatively high Z materials such as lead, tungsten and depleted uranium and lower Z materials such as steel, copper and tin? (3) How well will such systems operate for a uranium material which is an intermediate case between low density yellowcake and high density depleted uranium metal? These questions have led us to develop a set of phantoms to help answer these questions, but do not have any direct bearing on any smuggling concern. These new phantoms are designed to allow a systemic exploration of these questions by gradually varying their compositions and thicknesses. These phantoms are also good probes of the blurring behavior of radiography and tomography systems. These phantoms are composed of steel ({rho} assumed to be 7.8 g/cc), lead ({rho} assumed to be 11.4 g/cc), tungsten ({rho} assumed to be 19.25 g/cc), uranium oxide (UO{sub 3}) ({rho} assumed to be 4.6 g/cc), and depleted uranium (DU) ({rho} assumed to be 18.9 g/cc). There are five designed phantoms described in this report: (1) Cylindrical shells of Tungsten and Steel; (2) Depleted Uranium Inside Tungsten Hemi-cube Shells; (3) Nested Spherical Shells; (4) UO{sub 3} Cylinder; and (5) Shielded DU Sphere.

Aufderheide, M B; Martz, H E; Curtin, M

2009-06-22T23:59:59.000Z

313

Comparison of electrical capacitance tomography and gamma densitometer measurement in viscous oil-gas flows  

SciTech Connect (OSTI)

Multiphase flow is a common occurrence in industries such as nuclear, process, oil and gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil and gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oil (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 and 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 and 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.

Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi [Department of Offshore Process and Energy Systems Engineering, Cranfield University, Cranfield (United Kingdom)

2014-04-11T23:59:59.000Z

314

Characterization of conditional state-engineering quantum processes by coherent state quantum process tomography  

E-Print Network [OSTI]

Conditional quantum optical processes enable a wide range of technologies from generation of highly non-classical states to implementation of quantum logic operations. The process fidelity that can be achieved in a realistic implementation depends on a number of system parameters. Here we experimentally examine Fock-state filtration, a canonical example of a broad class of conditional quantum operations acting on a single optical field mode. This operation is based upon interference of the mode to be manipulated with an auxiliary single-photon state at a beam splitter, resulting in the entanglement of the two output modes. A conditional projective measurement onto a single photon at one output mode heralds the success of the process. This operation, which implements a measurement-induced nonlinearity, is capable of suppressing particular photon-number probability amplitudes of an arbitrary quantum state. We employ coherent-state process tomography to determine the precise operation realized in our experiment. To identify the key sources of experimental imperfection, we develop a model of the process and identify three main contributions that significantly hamper its efficacy. The reconstructed tensor is compared with a model of the process taking into account sources of experimental imperfection with fidelity better than 0.95. This enables us to identify three key challenges to overcome in realizing a filter with high fidelity - namely the single-photon nature of the auxiliary state, high-mode overlap, and the need for number resolving detection when heralding. The results show that the filter does indeed exhibit a nonlinear response as a function of input photon number and preserves the phase relation between Fock layers of the output state, providing promise for future applications.

Merlin Cooper; Eirion Slade; Michal Karpinski; Brian J. Smith

2014-10-25T23:59:59.000Z

315

Construction and Test of Low Cost X-Ray Tomography Scanner for Physical-Chemical Analysis and Nondestructive Inspections  

SciTech Connect (OSTI)

X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe the development of a low cost micro-CT X-ray scanner that is being developed for nondestructive testing. This tomograph operates using a microfocus X-ray source and contains a silicon photodiode as detectors. The performance of the system, by its spatial resolution, has been estimated through its Modulation Transfer Function-MTF and the obtained value at 10% of MTF is 661 {mu}m. It was built as a general purpose nondestructive testing device.

Oliveira, Jose Martins Jr. de [Universidade de Sorocaba-UNISO, Campus Seminario, Caixa Postal 578, Av. Dr. Eugenio Salermo, 100, Centro, 18035-430, Sorocaba, SP (Brazil); Martins, Antonio Cesar Germano [Universidade Estadual Paulista Julio de Mesquita Filho-UNESP, GASI, Av. 3 de Marco, 511, Alto da Boa Vista, 18087-180, Sorocaba, SP (Brazil)

2009-06-03T23:59:59.000Z

316

In-situ monitoring of surface post-processing in large aperture fused silica optics with Optical Coherence Tomography  

SciTech Connect (OSTI)

Optical Coherence Tomography is explored as a method to image laser-damage sites located on the surface of large aperture fused silica optics during post-processing via CO{sub 2} laser ablation. The signal analysis for image acquisition was adapted to meet the sensitivity requirements for this application. A long-working distance geometry was employed to allow imaging through the opposite surface of the 5-cm thick optic. The experimental results demonstrate the potential of OCT for remote monitoring of transparent material processing applications.

Guss, G M; Bass, I l; Hackel, R P; Mailhiot, C; Demos, S G

2008-02-08T23:59:59.000Z

317

Enhancement of the resolution of full-field optical coherence tomography by using a colour image sensor  

SciTech Connect (OSTI)

The influence of white balance in a colour image detector on the resolution of a full-field optical coherence tomograph (FFOCT) is studied. The change in the interference pulse width depending on the white balance tuning is estimated in the cases of a thermal radiation source (incandescent lamp) and a white light emitting diode. It is shown that by tuning white balance of the detector in a certain range, the FFOCT resolution can be increased by 20 % as compared to the resolution, attained with the use of a monochrome detector. (optical coherence tomography)

Kalyanov, A L; Lychagov, V V; Smirnov, I V; Ryabukho, V P [N.G. Chernyshevsky Saratov State University, Saratov (Russian Federation)

2013-08-31T23:59:59.000Z

318

Nonrigid registration-based coronary artery motion correction for cardiac computed tomography  

SciTech Connect (OSTI)

Purpose: X-ray computed tomography angiography (CTA) is the modality of choice to noninvasively monitor and diagnose heart disease with coronary artery health and stenosis detection being of particular interest. Reliable, clinically relevant coronary artery imaging mandates high spatiotemporal resolution. However, advances in intrinsic scanner spatial resolution (CT scanners are available which combine nearly 900 detector columns with focal spot oversampling) can be tempered by motion blurring, particularly in patients with unstable heartbeats. As a result, recently numerous methods have been devised to improve coronary CTA imaging. Solutions involving hardware, multisector algorithms, or {beta}-blockers are limited by cost, oversimplifying assumptions about cardiac motion, and populations showing contraindications to drugs, respectively. This work introduces an inexpensive algorithmic solution that retrospectively improves the temporal resolution of coronary CTA without significantly affecting spatial resolution. Methods: Given the goal of ruling out coronary stenosis, the method focuses on 'deblurring' the coronary arteries. The approach makes no assumptions about cardiac motion, can be used on exams acquired at high heart rates (even over 75 beats/min), and draws on a fast and accurate three-dimensional (3D) nonrigid bidirectional labeled point matching approach to estimate the trajectories of the coronary arteries during image acquisition. Motion compensation is achieved by employing a 3D warping of a series of partial reconstructions based on the estimated motion fields. Each of these partial reconstructions is created from data acquired over a short time interval. For brevity, the algorithm 'Subphasic Warp and Add' (SWA) reconstruction. Results: The performance of the new motion estimation-compensation approach was evaluated by a systematic observer study conducted using nine human cardiac CTA exams acquired over a range of average heart rates between 68 and 86 beats/min. Algorithm performance was based-lined against exams reconstructed using standard filtered-backprojection (FBP). The study was performed by three experienced reviewers using the American Heart Association's 15-segment model. All vessel segments were evaluated to quantify their viability to allow a clinical diagnosis before and after motion estimation-compensation using SWA. To the best of the authors' knowledge this is the first such observer study to show that an image processing-based software approach can improve the clinical diagnostic value of CTA for coronary artery evaluation. Conclusions: Results from the observer study show that the SWA method described here can dramatically reduce coronary artery motion and preserve real pathology, without affecting spatial resolution. In particular, the method successfully mitigated motion artifacts in 75% of all initially nondiagnostic coronary artery segments, and in over 45% of the cases this improvement was enough to make a previously nondiagnostic vessel segment clinically diagnostic.

Bhagalia, Roshni; Pack, Jed D.; Miller, James V.; Iatrou, Maria [GE Global Research, Niskayuna, New York 12309 (United States); GE Healthcare, Hoboken, New Jersey 07030 (United States)

2012-07-15T23:59:59.000Z

319

(/sup 11/C)clorgyline and (/sup 11/C)-L-deprenyl and their use in measuring functional monoamine oxidase activity in the brain using positron emission tomography  

DOE Patents [OSTI]

This invention involves a new strategy for imaging the activity of the enzyme monoamine oxidase in the living body by using /sup 11/C-labeled enzyme inhibitors which bind irreversibly to an enzyme as a result of catalysis. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

1986-04-17T23:59:59.000Z

320

Re-Inversion of Surface Electrical Resistivity Tomography Data from the Hanford Site B-Complex  

SciTech Connect (OSTI)

This report documents the three-dimensional (3D) inversion results of surface electrical resistivity tomography (ERT) data collected over the Hanford Site B-Complex. The data were collected in order to image the subsurface distribution of electrically conductive vadose zone contamination resulting from both planned releases of contamination into subsurface infiltration galleries (cribs, trenches, and tile fields), as well as unplanned releases from the B, BX, and BY tank farms and/or associated facilities. Electrically conductive contaminants are those which increase the ionic strength of pore fluids compared to native conditions, which comprise most types of solutes released into the subsurface B-Complex. The ERT data were collected and originally inverted as described in detail in report RPP-34690 Rev 0., 2007, which readers should refer to for a detailed description of data collection and waste disposal history. Although the ERT imaging results presented in that report successfully delineated the footprint of vadose zone contamination in areas outside of the tank farms, imaging resolution was not optimized due to the inability of available inversion codes to optimally process the massive ERT data set collected at the site. Recognizing these limitations and the potential for enhanced ERT characterization and time-lapse imaging at contaminated sites, a joint effort was initiated in 2007 by the U.S. Department of Energy – Office of Science (DOE-SC), with later support by the Office of Environmental Management (DOE-EM), and the U.S. Department of Defense (DOD), to develop a high-performance distributed memory parallel 3D ERT inversion code capable of optimally processing large ERT data sets. The culmination of this effort was the development of E4D (Johnson et al., 2010,2012) In 2012, under the Deep Vadose Zone Applied Field Research Initiative (DVZ-AFRI), the U.S. Department of Energy – Richland Operations Office (DOE-RL) and CH2M Hill Plateau Remediation Company (CHPRC) commissioned an effort for the Pacific Northwest National Laboratory (PNNL) to re-invert the ERT data collected over the B-Complex using E4D, with the objective to improve imaging resolution and better understand the distribution of vadose zone contamination at the B-Complex. The details and results of that effort as documented in this report display a significant improvement in ERT image resolution, revealing the nature and orientation of contaminant plumes originating in former infiltration galleries and extending toward the water table. In particular, large plumes originating in the BY-Cribs area appear to have intercepted, or are close to intercepting the water table after being diverted eastward, possibly by the same low permeability unit causing perched water north of the B-Tank Farm boundary. Contaminant plumes are also evident beneath the BX-Trenches, but do not appear to have intercepted the water table. Imaging results within the tank farms themselves are highly biased by the dense network of electrically conductive tanks and dry wells, and are therefore inconclusive concerning contaminant distributions beneath tanks. However, beneath the diversion boxes, the results do reveal highly conductive anomalies that are not associated with metallic infrastructure, and may be diagnostic of extensive contamination. Overall, the parallel ERT inversion provides additional detail concerning contaminated zones in terms of conductive anomalies. These anomalies are consistent with waste disposal histories, and in several cases reveal lateral contaminant transport caused by heterogeneity within the vadose zone.

Johnson, Timothy C.; Wellman, Dawn M.

2013-05-01T23:59:59.000Z

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321

Model reliability for 3D electrical resistivity tomography: Application of the volume of investigation index to a time-lapse monitoring experiment  

E-Print Network [OSTI]

Model reliability for 3D electrical resistivity tomography: Application of the volume reliability for 3D ERTand as a method of survey design. We show how the VOI provides a measure of model, we utilize the VOI for judging the degree of reliability of hydrogeologi- cal interpretations

Barrash, Warren

322

Selection of dimensions of scintillation detectors and of the correction energy with the use of the dual energy method in computerized tomography  

SciTech Connect (OSTI)

The article explains the method of selecting the optimum energy for correcting the energy selectivity of tomographic projection and the optimum length of the crystals corresponding to it when the dual energy method in computerized tomography is used. The results of numerical calculations for actual materials and of the registration by count are presented.

Zav'yalkin, F.M.; Osipov, S.P.

1986-05-01T23:59:59.000Z

323

Three-dimensional imaging of copper pillars using x-ray tomography within a scanning electron microscope: A simulation study based on synchrotron data  

SciTech Connect (OSTI)

While microelectronic devices are frequently characterized with surface-sensitive techniques having nanometer resolution, interconnections used in 3D integration require 3D imaging with high penetration depth and deep sub-micrometer spatial resolution. X-ray tomography is well adapted to this situation. In this context, the purpose of this study is to assess a versatile and turn-key tomographic system allowing for 3D x-ray nanotomography of copper pillars. The tomography tool uses the thin electron beam of a scanning electron microscope (SEM) to provoke x-ray emission from specific metallic targets. Then, radiographs are recorded while the sample rotates in a conventional cone beam tomography scheme that ends up with 3D reconstructions of the pillar. Starting from copper pillars data, collected at the European Synchrotron Radiation Facility, we build a 3D numerical model of a copper pillar, paying particular attention to intermetallics. This model is then used to simulate physical radiographs of the pillar using the geometry of the SEM-hosted x-ray tomography system. Eventually, data are reconstructed and it is shown that the system makes it possible the quantification of 3D intermetallics volume in copper pillars. The paper also includes a prospective discussion about resolution issues.

Martin, N.; Bertheau, J.; Charbonnier, J.; Hugonnard, P.; Lorut, F. [ST Microelectronics, 850 Rue Jean Monnet, 38920 Crolles (France); Bleuet, P.; Tabary, J. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Laloum, D. [ST Microelectronics, 850 Rue Jean Monnet, 38920 Crolles (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

2013-02-15T23:59:59.000Z

324

ModPET: A Novel Small-Animal PET System Positron Emission Tomography (PET) and PET/CT systems have become the gold standard for imaging  

E-Print Network [OSTI]

ModPET: A Novel Small-Animal PET System Positron Emission Tomography (PET) and PET/CT systems have these results to their human counterparts. Current small-animal PET scanners are very costly and complicated for Gamma-Ray Imaging, we are developing a novel small-animal PET scanner that utilizes common modular

Arizona, University of

325

Spatial modeling of the 3D morphology of hybrid polymer-ZnO solar cells, based on electron tomography data  

E-Print Network [OSTI]

A spatial stochastic model is developed which describes the 3D nanomorphology of composite materials, being blends of two different (organic and inorganic) solid phases. Such materials are used, for example, in photoactive layers of hybrid polymer zinc oxide solar cells. The model is based on ideas from stochastic geometry and spatial statistics. Its parameters are fitted to image data gained by electron tomography (ET), where adaptive thresholding and stochastic segmentation have been used to represent morphological features of the considered ET data by unions of overlapping spheres. Their midpoints are modeled by a stack of 2D point processes with a suitably chosen correlation structure, whereas a moving-average procedure is used to add the radii of spheres. The model is validated by comparing physically relevant characteristics of real and simulated data, like the efficiency of exciton quenching, which is important for the generation of charges and their transport toward the electrodes.

O. Stenzel; V. Schmidt; H. Hassfeld; R. Thiedmann; L. J. A. Koster; S. D. Oosterhout; S. S. van Bavel; M. M. Wienk; J. Loos; R. A. J. Janssen

2011-11-22T23:59:59.000Z

326

Stability of nanoclusters in 14YWT oxide dispersion strengthened steel under heavy ion-irradiation by atom probe tomography  

SciTech Connect (OSTI)

14YWT oxide dispersion strengthened (ODS) ferritic steel was irradiated with of 5 MeV Ni2+ ions, at 300 C, 450 C, and 600 C to a damage level of 100 dpa. The stability of Ti–Y–O nanoclusters was investigated by applying atom probe tomography (APT) in voltage mode, of the samples before and after irradiations. The average size and number density of the nanoclusters was determined using the maximum separation method. These techniques allowed for the imaging of nanoclusters to sizes well below the resolution limit of conventional transmission electron microscopy techniques. The most significant changes were observed for samples irradiated at 300 C where the size (average Guinier radius) and number density of nanoclusters were observed to decrease from 1.1 nm to 0.8 nm and 12 1023 to 3.6 1023, respectively. In this study, the nanoclusters are more stable at higher temperature.

Jianchao He; Farong Wan; Kumar Sridharan; Todd R. Allen; A. Certain; V. Shutthanandan; Y.Q. Wu

2014-12-01T23:59:59.000Z

327

Computed tomography and optical remote sensing: Development for the study of indoor air pollutant transport and dispersion  

SciTech Connect (OSTI)

This thesis investigates the mixing and dispersion of indoor air pollutants under a variety of conditions using standard experimental methods. It also extensively tests and improves a novel technique for measuring contaminant concentrations that has the potential for more rapid, non-intrusive measurements with higher spatial resolution than previously possible. Experiments conducted in a sealed room support the hypothesis that the mixing time of an instantaneously released tracer gas is inversely proportional to the cube root of the mechanical power transferred to the room air. One table-top and several room-scale experiments are performed to test the concept of employing optical remote sensing (ORS) and computed tomography (CT) to measure steady-state gas concentrations in a horizontal plane. Various remote sensing instruments, scanning geometries and reconstruction algorithms are employed. Reconstructed concentration distributions based on existing iterative CT techniques contain a high degree of unrealistic spatial variability and do not agree well with simultaneously gathered point-sample data.

Drescher, A.C.

1995-06-01T23:59:59.000Z

328

Stability Of Nanoclusters In 14YWT Oxide Dispersion Strengthened Steel Under Heavy Ion-irradiation By Atom Probe Tomography  

SciTech Connect (OSTI)

14YWT oxide dispersion strengthened (ODS) ferritic steel was irradiated with of 5 MeV Ni2+ ions, at 300 °C, 450 °C, and 600 °C to a damage level of 100 dpa. The stability of Ti–Y–O nanoclusters was investigated by applying atom probe tomography (APT) in voltage mode, of the samples before and after irradiations. The average size and number density of the nanoclusters was determined using the maximum separation method. These techniques allowed for the imaging of nanoclusters to sizes well below the resolution limit of conventional transmission electron microscopy techniques. The most significant changes were observed for samples irradiated at 300 °C where the size (average Guinier radius) and number density of nanoclusters were observed to decrease from 1.1 nm to 0.8 nm and 12 × 1023 to 3.6 × 1023, respectively. In this study, the nanoclusters are more stable at higher temperature.

He, Jianchao; Wan, F.; Sridharan, Kumar; Allen, Todd R.; Certain, Alicia G.; Shutthanandan, V.; Wu, Yaqiao

2014-12-01T23:59:59.000Z

329

The Potential Role of Optical Coherence Tomography in the Evaluation of Vulnerable Carotid Atheromatous Plaques: A Pilot Study  

SciTech Connect (OSTI)

Purpose. The decision to intervene surgically in patients with carotid artery disease is based on the presence of symptoms, along with the severity of carotid artery stenosis as assessed by ultrasound or X-ray computed tomography (CT). Optical coherence tomography (OCT) is a relatively new imaging technique that offers potential in the identification of, as well as the distinction between, stable and unstable atherosclerotic plaques. The purpose of our study was to evaluate whether OCT can be used as a noninvasive diagnostic tool to reveal the morphology of carotid stenosis from the adventitial surface of the carotid artery. To achieve this aim, excised atheromatous plaques were scanned by OCT from the external surface. Methods. Plaques removed at carotid endarterectomy were scanned by OCT from the external surface within 72 hr of surgery and then examined histologically. The images of the histologic slides and the scans were then compared. Results. We examined 10 carotid endarterectomy specimens and were able to identify calcification, cholesterol crystal clefts, and lipid deposits in the OCT images with histologic correlation. The strong light scattering from the calcified tissue and cholesterol crystal clefts limited the depth of light penetration, making observation of the intimal surface and the detail of the fibrous cap difficult. However, we were able to confidently identify the absence of an atherosclerotic plaque by OCT scans even from the external surface. Conclusion. The results of this pilot study demonstrate that OCT can reveal the main features of carotid stenosis but that plaque vulnerability cannot be reliably and precisely assessed if scanned from the external surface with OCT in its present form.

Prabhudesai, Vikramaditya [St. Joseph's Hospital, Diagnostic Imaging (Canada); Phelan, Cordelia [University Hospital of North Staffordshire, NHS Trust, Department of Pathology (United Kingdom); Yang, Ying [Institute of Science and Technology in Medicine, Keele University (United Kingdom)], E-mail: bea00@keele.ac.uk; Wang, Ruikang K. [Oregon Health and Science University, Department of Biomedical Engineering (United States); Cowling, Mark G. [University Hospital of North Staffordshire, NHS Trust, Department of Radiology (United Kingdom)

2006-12-15T23:59:59.000Z

330

Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator  

SciTech Connect (OSTI)

In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the time-averaged void distribution in these loops. Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed. In this article, three axially symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm, and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper. Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020, and 0.022 cm{sup ?1}, solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.

Andersson, P., E-mail: peter.andersson@physics.uu.se; Andersson-Sunden, E.; Sjöstrand, H.; Jacobsson-Svärd, S. [Department of Physics and Astronomy, Division of Applied Nuclear Physics, Uppsala University, Lägerhyddsgatan 1, 751 20 Uppsala (Sweden)

2014-08-01T23:59:59.000Z

331

Attenuation Tomography of Northern California and the Yellow Sea / Korean Peninsula from Coda-source Normalized and Direct Lg Amplitudes  

SciTech Connect (OSTI)

Inversions for regional attenuation (1/Q) of Lg are performed in two different regions. The path attenuation component of the Lg spectrum is isolated using the coda-source normalization method, which corrects the Lg spectral amplitude for the source using the stable, coda-derived source spectra. Tomographic images of Northern California agree well with one-dimensional (1-D) Lg Q estimated from five different methods. We note there is some tendency for tomographic smoothing to increase Q relative to targeted 1-D methods. For example in the San Francisco Bay Area, which contains high attenuation relative to the rest of it's region, Q is over-estimated by {approx}30. Coda-source normalized attenuation tomography is also carried out for the Yellow Sea/Korean Peninsula (YSKP) where output parameters (site, source, and path terms) are compared with those from the amplitude tomography method of Phillips et al. (2005) as well as a new method that ties the source term to the MDAC formulation (Walter and Taylor, 2001). The source terms show similar scatter between coda-source corrected and MDAC source perturbation methods, whereas the amplitude method has the greatest correlation with estimated true source magnitude. The coda-source better represents the source spectra compared to the estimated magnitude and could be the cause of the scatter. The similarity in the source terms between the coda-source and MDAC-linked methods shows that the latter method may approximate the effect of the former, and therefore could be useful in regions without coda-derived sources. The site terms from the MDAC-linked method correlate slightly with global Vs30 measurements. While the coda-source and amplitude ratio methods do not correlate with Vs30 measurements, they do correlate with one another, which provides confidence that the two methods are consistent. The path Q{sup -1} values are very similar between the coda-source and amplitude ratio methods except for small differences in the Da-xin-anling Mountains, in the northern YSKP. However there is one large difference between the MDAC-linked method and the others in the region near stations TJN and INCN, which point to site-effect as the cause for the difference.

Ford, S R; Dreger, D S; Phillips, W S; Walter, W R; Mayeda, K; Malagnini, L

2008-07-16T23:59:59.000Z

332

Comparison of Computed Tomography and Cineangiography in the Demonstration of Central Pulmonary Arteries in Cyanotic Congenital Heart Disease  

SciTech Connect (OSTI)

Purpose: To assess the diagnostic accuracy of contrast-enhanced computed tomography (CT) for central pulmonary artery pathology in patients with cyanotic congenital heart disease (CCHD) and right ventricular outflow obstruction. Methods: We compared contrast-enhanced CT and cine pulmonary arteriography in 24 patients with CCHD to assess central pulmonary arteries including the confluence. Both investigations were interpreted by a cardiac radiologist in a double-blinded manner at an interval of 3 weeks. Angiography was used as the gold standard for comparison. Results: The sensitivity for visualization of main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), and confluence on CT was 94%, 100%, 92.8%, and 92.8%, respectively. Diagnostic specificity for the same entities was 28.5%, 100%, 80%, and 50%, respectively. The positive predictive value for each was 76.2%, 100%, 94.1%, and 72.2%, respectively. The low specificity of CT in the evaluation of the MPA and the confluence is perhaps due to distorted right ventricular outflow anatomy in CCHD. Large aortopulmonary collaterals in this region were mistaken for the MPA in some patients with pulmonary atresia. Conclusion: CT is a useful, relatively noninvasive, imaging technique for the central pulmonary arteries in selected patients. It can supplement diagnostic information from angiography but cannot replace it. LPA demonstration on axial images alone is inadequate.

Taneja, Karuna; Sharma, Sanjiv [Department of Cardiovascular Radiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India); Kumar, Krishan [Department of Cardiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India); Rajani, Mira [Department of Cardiovascular Radiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India)

1996-03-15T23:59:59.000Z

333

Accurate measurement of relative tilt and azimuth angles in electron tomography: A comparison of fiducial marker method with electron diffraction  

SciTech Connect (OSTI)

Electron tomography is a method whereby a three-dimensional reconstruction of a nanoscale object is obtained from a series of projected images measured in a transmission electron microscope. We developed an electron-diffraction method to measure the tilt and azimuth angles, with Kikuchi lines used to align a series of diffraction patterns obtained with each image of the tilt series. Since it is based on electron diffraction, the method is not affected by sample drift and is not sensitive to sample thickness, whereas tilt angle measurement and alignment using fiducial-marker methods are affected by both sample drift and thickness. The accuracy of the diffraction method benefits reconstructions with a large number of voxels, where both high spatial resolution and a large field of view are desired. The diffraction method allows both the tilt and azimuth angle to be measured, while fiducial marker methods typically treat the tilt and azimuth angle as an unknown parameter. The diffraction method can be also used to estimate the accuracy of the fiducial marker method, and the sample-stage accuracy. A nano-dot fiducial marker measurement differs from a diffraction measurement by no more than ±1°.

Hayashida, Misa [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Malac, Marek; Egerton, Ray F. [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton T6G 2M9 (Canada); Department of Physics, University of Alberta, Edmonton T6H 2E1 (Canada); Bergen, Michael; Li, Peng [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton T6G 2M9 (Canada)

2014-08-15T23:59:59.000Z

334

Spatial variation of void ratio and shear band thickness in sand using X-ray computed tomography  

SciTech Connect (OSTI)

A detailed study of spatial variation of void ratio and shear band thickness measurements is presented in this paper. A prismatic sand specimen that initially measured 57{center_dot}4 mm wide x 120{center_dot}5 mm long x 182{center_dot}1 mm high was sheared under plane-strain (biaxial) loading conditions. The specimen was prepared at a relative density of 79% using F-75 Ottawa sand. X-ray computed tomography was used to scan the specimen before shearing and after the onset of the shear band. The specimen failed through a single shear band with an inclination angle of 65{center_dot}6{sup o} measured from the direction of the minor principal stress. Computer algorithms were developed to calibrate CT images and quantify void ratio (e) variation within the specimen. CT data analysis revealed cross-sectional spatial variation in void ratio where density is higher in regions close to the edges of the specimen due to membrane effects and confining pressure with no significant variation in void ratio in the axial direction (top to bottom) before shearing. The shear band was easily identified from the CT images, and analysis of void ratio showed a noticeable jump in void ratio profile across the shear band. A detailed statistical summary of the thickness of the shear band and variation of void ratio across the shear band is presented and discussed.

Alshibli, K.A.; Hasan, A. (LSU)

2008-05-01T23:59:59.000Z

335

Laboratory-Based Cryogenic Soft X-ray Tomography with Correlative Cryo-Light and Electron Microscopy  

SciTech Connect (OSTI)

Here we present a novel laboratory-based cryogenic soft X-ray microscope for whole cell tomography of frozen hydrated samples. We demonstrate the capabilities of this compact cryogenic microscope by visualizing internal sub-cellular structures of Saccharomyces cerevisiae cells. The microscope is shown to achieve better than 50 nm spatial resolution with a Siemens star test sample. For whole biological cells, the microscope can image specimens up to 5 micrometers thick. Structures as small as 90 nm can be detected in tomographic reconstructions at roughly 70 nm spatial resolution following a low cumulative radiation dose of only 7.2 MGy. Furthermore, the design of the specimen chamber utilizes a standard sample support that permits multimodal correlative imaging of the exact same unstained yeast cell via cryo-fluorescence light microscopy, cryo-soft x-ray microscopy and cryo-transmission electron microscopy. This completely laboratory-based cryogenic soft x-ray microscope will therefore enable greater access to three-dimensional ultrastructure determination of biological whole cells without chemical fixation or physical sectioning.

Carlson, David B.; Gelb, Jeff; Palshin, Vadim; Evans, James E.

2013-02-01T23:59:59.000Z

336

Quantum state tomography of large nuclear spins in a semiconductor quantum well: Robustness against errors as quantified by condition numbers  

E-Print Network [OSTI]

We discuss methods of quantum state tomography for solid-state systems with a large nuclear spin $I=3/2$ in nanometer-scale semiconductors devices based on a quantum well. Due to quadrupolar interactions, the Zeeman levels of these nuclear-spin devices become nonequidistant, forming a controllable four-level quantum system (known as quartit or ququart). The occupation of these levels can be selectively and coherently manipulated by multiphoton transitions using the techniques of nuclear magnetic resonance (NMR) [Yusa et al., Nature (London) 434, 101 (2005)]. These methods are based on an unconventional approach to NMR, where the longitudinal magnetization $M_z$ is directly measured. This is in contrast to the standard NMR experiments and tomographic methods, where the transverse magnetization $M_{xy}$ is detected. The robustness against errors in the measured data is analyzed by using condition numbers. We propose several methods with optimized sets of rotations. The optimization is applied to decrease the number of NMR readouts and to improve the robustness against errors, as quantified by condition numbers. An example of state reconstruction, using Monte Carlo methods, is presented. Tomographic methods for quadrupolar nuclei with higher-spin numbers (including $I=7/2$) are also described.

Adam Miranowicz; Sahin K. Ozdemir; Jiri Bajer; Go Yusa; Nobuyuki Imoto; Yoshiro Hirayama; Franco Nori

2014-10-09T23:59:59.000Z

337

Tensile testing of materials at high temperatures above 1700?°C with in situ synchrotron X-ray micro-tomography  

SciTech Connect (OSTI)

A compact ultrahigh temperature tensile testing instrument has been designed and fabricated for in situ x-ray micro-tomography using synchrotron radiation at the Advanced Light Source, Lawrence Berkeley National Laboratory. It allows for real time x-ray micro-tomographic imaging of test materials under mechanical load at temperatures up to 2300?°C in controlled environments (vacuum or controlled gas flow). Sample heating is by six infrared halogen lamps with ellipsoidal reflectors arranged in a confocal configuration, which generates an approximately spherical zone of high heat flux approximately 5 mm in diameter. Samples are held between grips connected to a motorized stage that loads the samples in tension or compression with forces up to 2.2 kN. The heating chamber and loading system are water-cooled for thermal stability. The entire instrument is mounted on a rotation stage that allows stepwise recording of radiographs over an angular range of 180°. A thin circumferential (360°) aluminum window in the wall of the heating chamber allows the x-rays to pass through the chamber and the sample over the full angular range. The performance of the instrument has been demonstrated by characterizing the evolution of 3D damage mechanisms in ceramic composite materials under tensile loading at 1750?°C.

Haboub, Abdel; Nasiatka, James R.; MacDowell, Alastair A. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Bale, Hrishikesh A. [Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Cox, Brian N.; Marshall, David B. [Teledyne Scientific Company, Thousand Oaks, California 91360 (United States); Ritchie, Robert O., E-mail: roritchie@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States)

2014-08-15T23:59:59.000Z

338

Atom probe tomography studies of Al{sub 2}O{sub 3} gate dielectrics on GaN  

SciTech Connect (OSTI)

Atom probe tomography was used to achieve three-dimensional characterization of in situ Al{sub 2}O{sub 3}/GaN structures grown by metal organic chemical vapor deposition (MOCVD). Al{sub 2}O{sub 3} dielectrics grown at three different temperatures of 700, 900, and 1000?°C were analyzed and compared. A low temperature GaN cap layer grown atop Al{sub 2}O{sub 3} enabled a high success rate in the atom probe experiments. The Al{sub 2}O{sub 3}/GaN interfaces were found to be intermixed with Ga, N, and O over the distance of a few nm. Impurity measurements data showed that the 1000?°C sample contains higher amounts of C (4?×?10{sup 19}/cm{sup 3}) and lower amounts of H (7?×?10{sup 19}/cm{sup 3}), whereas the 700?°C sample exhibits lower C impurities (<10{sup 17}/cm{sup 3}) and higher H incorporation (2.2?×?10{sup 20}/cm{sup 3}). On comparing with Al{sub 2}O{sub 3} grown by atomic layer deposition (ALD), it was found that the MOCVD Al{sub 2}O{sub 3}/GaN interface is comparatively abrupt. Scanning transmission electron microscopy data showed that the 900?°C and 1000?°C MOCVD films exhibit polycrystalline nature, while the ALD films were found to be amorphous.

Mazumder, Baishakhi, E-mail: bmazumder@engineering.ucsb.edu; Wu, Feng; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Liu, Xiang; Yeluri, Ramya; Mishra, Umesh K. [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)

2014-10-07T23:59:59.000Z

339

Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization  

SciTech Connect (OSTI)

Purpose: Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patient's electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition. Methods: The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization. Results: 4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patient's left ventricular ejection fraction. Conclusions: 4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.

Mory, Cyril, E-mail: cyril.mory@philips.com [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France); Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France); Auvray, Vincent; Zhang, Bo [Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France)] [Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France); Grass, Michael; Schäfer, Dirk [Philips Research, Röntgenstrasse 24–26, D-22335 Hamburg (Germany)] [Philips Research, Röntgenstrasse 24–26, D-22335 Hamburg (Germany); Chen, S. James; Carroll, John D. [Department of Medicine, Division of Cardiology, University of Colorado Denver, 12605 East 16th Avenue, Aurora, Colorado 80045 (United States)] [Department of Medicine, Division of Cardiology, University of Colorado Denver, 12605 East 16th Avenue, Aurora, Colorado 80045 (United States); Rit, Simon [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon (France); Université Lyon 1 (France); Centre Léon Bérard, 28 rue Laënnec, F-69373 Lyon (France); Peyrin, Françoise [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France); X-ray Imaging Group, European Synchrotron, Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Douek, Philippe; Boussel, Loïc [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon (France); Université Lyon 1 (France); Hospices Civils de Lyon, 28 Avenue du Doyen Jean Lépine, 69500 Bron (France)

2014-02-15T23:59:59.000Z

340

Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)  

SciTech Connect (OSTI)

The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO{sub 4}) solution. As a tissue-staining contrast agent, OsO{sub 4} is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO{sub 4} preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE{sup -/-}) mice at 10 {mu}m resolution. The results show that walls of coronary arteries as small as 45 {mu}m in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO{sub 4} and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han (NIH)

2012-05-10T23:59:59.000Z

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341

Impact of Computed Tomography Image Quality on Image-Guided Radiation Therapy Based on Soft Tissue Registration  

SciTech Connect (OSTI)

Purpose: In image-guided radiation therapy (IGRT), different computed tomography (CT) modalities with varying image quality are being used to correct for interfractional variations in patient set-up and anatomy changes, thereby reducing clinical target volume to the planning target volume (CTV-to-PTV) margins. We explore how CT image quality affects patient repositioning and CTV-to-PTV margins in soft tissue registration-based IGRT for prostate cancer patients. Methods and Materials: Four CT-based IGRT modalities used for prostate RT were considered in this study: MV fan beam CT (MVFBCT) (Tomotherapy), MV cone beam CT (MVCBCT) (MVision; Siemens), kV fan beam CT (kVFBCT) (CTVision, Siemens), and kV cone beam CT (kVCBCT) (Synergy; Elekta). Daily shifts were determined by manual registration to achieve the best soft tissue agreement. Effect of image quality on patient repositioning was determined by statistical analysis of daily shifts for 136 patients (34 per modality). Inter- and intraobserver variability of soft tissue registration was evaluated based on the registration of a representative scan for each CT modality with its corresponding planning scan. Results: Superior image quality with the kVFBCT resulted in reduced uncertainty in soft tissue registration during IGRT compared with other image modalities for IGRT. The largest interobserver variations of soft tissue registration were 1.1 mm, 2.5 mm, 2.6 mm, and 3.2 mm for kVFBCT, kVCBCT, MVFBCT, and MVCBCT, respectively. Conclusions: Image quality adversely affects the reproducibility of soft tissue-based registration for IGRT and necessitates a careful consideration of residual uncertainties in determining different CTV-to-PTV margins for IGRT using different image modalities.

Morrow, Natalya V.; Lawton, Colleen A. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Qi, X. Sharon [Department of Radiation Oncology, University of Colorado Denver, Denver, Colorado (United States); Li, X. Allen, E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)

2012-04-01T23:59:59.000Z

342

Breast Patient Setup Error Assessment: Comparison of Electronic Portal Image Devices and Cone-Beam Computed Tomography Matching Results  

SciTech Connect (OSTI)

Purpose: To quantify the differences in setup errors measured with the cone-beam computed tomography (CBCT) and electronic portal image devices (EPID) in breast cancer patients. Methods and Materials: Repeat CBCT scan were acquired for routine offline setup verification in 20 breast cancer patients. During the CBCT imaging fractions, EPID images of the treatment beams were recorded. Registrations of the bony anatomy for CBCT to planning CT and EPID to digitally reconstructed-radiographs (DRRs) were compared. In addition, similar measurements of an anthropomorphic thorax phantom were acquired. Bland-Altman and linear regression analysis were performed for clinical and phantom registrations. Systematic and random setup errors were quantified for CBCT and EPID-driven correction protocols in the EPID coordinate system (U, V), with V parallel to the cranial-caudal axis and U perpendicular to V and the central beam axis. Results: Bland-Altman analysis of clinical EPID and CBCT registrations yielded 4 to 6-mm limits of agreement, indicating that both methods were not compatible. The EPID-based setup errors were smaller than the CBCT-based setup errors. Phantom measurements showed that CBCT accurately measures setup error whereas EPID underestimates setup errors in the cranial-caudal direction. In the clinical measurements, the residual bony anatomy setup errors after offline CBCT-based corrections were {Sigma}{sub U} = 1.4 mm, {Sigma}{sub V} = 1.7 mm, and {sigma}{sub U} = 2.6 mm, {sigma}{sub V} = 3.1 mm. Residual setup errors of EPID driven corrections corrected for underestimation were estimated at {Sigma}{sub U} = 2.2mm, {Sigma}{sub V} = 3.3 mm, and {sigma}{sub U} = 2.9 mm, {sigma}{sub V} = 2.9 mm. Conclusion: EPID registration underestimated the actual bony anatomy setup error in breast cancer patients by 20% to 50%. Using CBCT decreased setup uncertainties significantly.

Topolnjak, Rajko [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Sonke, Jan-Jakob, E-mail: j.sonke@nki.n [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Nijkamp, Jasper; Rasch, Coen; Minkema, Danny; Remeijer, Peter; Vliet-Vroegindeweij, Corine van [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

2010-11-15T23:59:59.000Z

343

Investigation of the Feasibility of Utilizing Gamma Emission Computed Tomography in Evaluating Fission Product Migration in Irradiated TRISO Fuel Experiments  

SciTech Connect (OSTI)

In the High Temperature Gas-Cooled Reactor (HTGR) the TRISO particle fuel serves as the primary fission product containment. However the large number of TRISO particles present in proposed HTGRs dictates that there will be a small fraction (~10-4 to 10-5) of as manufactured and in-pile particle failures that will lead to some fission product release. The matrix material surrounding the TRISO particles in fuel compacts and the structural graphite holding the TRISO particles in place can also serve as sinks for containing any released fission products. However data on the migration of solid fission products through these materials is lacking. One of the primary goals of the AGR-3/4 experiment is to study fission product migration from failed TRISO particles in prototypic HTGR components such as structural graphite and compact matrix material. In this work, the potential for a Gamma Emission Computed Tomography (GECT) technique to non-destructively examine the fission product distribution in AGR-3/4 components and other irradiation experiments is explored. Specifically, the feasibility of using the Idaho National Laboratory (INL) Hot Fuels Examination Facility (HFEF) Precision Gamma Scanner (PGS) system for this GECT application is considered. To test the feasibility, the response of the PGS system to idealized fission product distributions has been simulated using Monte Carlo radiation transport simulations. Previous work that applied similar techniques during the AGR-1 experiment will also be discussed as well as planned uses for the GECT technique during the post irradiation examination of the AGR-2 experiment. The GECT technique has also been applied to other irradiated nuclear fuel systems that were currently available in the HFEF hot cell including oxide fuel pins, metallic fuel pins, and monolithic plate fuel.

Jason M. Harp; Paul A. Demkowicz

2014-10-01T23:59:59.000Z

344

Out-of-Plane Computed-Tomography-Guided Biopsy Using a Magnetic-Field-Based Navigation System  

SciTech Connect (OSTI)

The purpose of this article is to report our clinical experience with out-of-plane computed-tomography (CT)-guided biopsies using a magnetic-field-based navigation system. Between February 2002 and March 2003, 20 patients underwent CT-guided biopsy in which an adjunct magnetic-field-based navigation system was used to aid an out-of-plane biopsy approach. Eighteen patients had an underlying primary malignancy. All biopsies involved the use of a coaxial needle system in which an outer 18G guide needle was inserted to the lesion using the navigation system and an inner 22G needle was then used to obtain fine-needle aspirates. Complications and technical success were recorded. Target lesions were located in the adrenal gland (n = 7), liver (n = 6), pancreas (n = 3), lung (n = 2), retroperitoneal lymph node (n = 1), and pelvis (n = 1). The mean lesion size (maximum transverse diameter) was 26.5 mm (range: 8-70 mm) and the mean and median cranial-caudal distance, between the transaxial planes of the final needle tip location and the needle insertion site, was 40 mm (range: 18-90 mm). Needle tip positioning was successfully placed within the lesion in all 20 biopsies. A diagnosis of malignancy was obtained in 14 biopsies. Benign diagnoses were encountered in the remaining six biopsies and included a benign adrenal gland (n = 2), fibroelastic tissue (n = 1), hepocytes with steatosis (n = 2) and reactive hepatocytes (n = 1). No complications were encountered. A magnetic-field-based navigation system is an effective adjunct tool for accurate and safe biopsy of lesions that require an out-of-plane CT approach.

Wallace, Michael J., E-mail: mwallace@di.mdacc.tmc.edu; Gupta, Sanjay; Hicks, Marshall E. [University of Texas M. D. Anderson Cancer Center, Departments of Diagnostic Radiology, Section of Vascular and Interventional Radiology (United States)

2006-02-15T23:59:59.000Z

345

Carbon monoxide line emission as a CMB foreground: tomography of the star-forming universe with different spectral resolutions  

E-Print Network [OSTI]

The rotational lines of carbon monoxide and the fine structure lines of CII and of the most abundant metals, emitted during the epoch of enhanced star formation in the universe, are redshifted in the frequency channels where the present-day and future CMB experiments are sensitive. We estimate the contribution to the CMB angular power spectrum by the emission in such lines in merging star-forming galaxies. We used the Lacey-Cole approach to characterize the distribution of the merging halos, together with a parametrization for the star formation rate in each of them. Using observational data from a sample of local, low-redshift, and high-redshift objects, we calibrated the luminosity in each line as a function of the star formation rate. We show that the correlation term arising from CO line emission is a significant source of foreground for CMB in a broad range of frequencies (in particular in the 20-60 GHz band) and for 1000tomography of the universe, by probing different redshift slices with varying thickness. (abridged)

Mattia Righi; Carlos Hernandez-Monteagudo; Rashid Sunyaev

2008-07-24T23:59:59.000Z

346

Routine sup 18 F-2-deoxy-2-fluoro-D-glucose ( sup 18 F-FDG) myocardial tomography using a normal large field of view gamma-camera  

SciTech Connect (OSTI)

There is a recent need to study glucose metabolism of the heart in ischemic, as well as in hibernating or stunned myocardium, and compare it with that in perfusion studies. In non-positron emission tomography centers, positron imaging is possible with a standard Anger-type camera if proper collimation and adequate shielding of the camera crystal can be achieved. For the study with fast-decaying isotopes, seven-pinhole tomography (7PHT), a limited-angle method designed for transaxial tomography of the left ventricle using a nonrotating camera, is well suited, because projections are acquired simultaneously. Individual adjustment (patient supine) of the camera's view axis (CAx) with the left ventricular axis (LVAx) gives excellent results: sensitivity for CHD 82%, specificity 72% in a prospective 201TI study (48 patients, x-ray coronarography as reference). Good alignment of CAx with LVAx is also achieved with the patient prone in LAO in a hammock above the camera surface. In this setting additional lead shielding of the camera is possible using a table reinforced with 5 cm of lead with a central hole for the 7PH-collimator, which has a special lead inlay. This allows utilization of the 511 KeV emitter 18F-FDG, which with a half-life of 109 minutes, can be transported a reasonable distance from the production site. System sensitivity and resolution for 18F was found comparable to 201Tl, 99mTc, and 123I using a phantom. First clinical examinations after 201Tl stress/redistribution studies showed increased 18F-FDG uptake in ischemic heart segments, as well as in hibernating nonperfused or stunned myocardium.

Hoeflin, F.L.; Ledermann, H.; Noelpp, U.; Weinreich, R.; Roesler, H. (Univ. of Berne, Inselspital (Switzerland))

1989-12-01T23:59:59.000Z

347

Comparison of Rigid and Adaptive Methods of Propagating Gross Tumor Volume Through Respiratory Phases of Four-Dimensional Computed Tomography Image Data Set  

SciTech Connect (OSTI)

Purpose: To compare three different methods of propagating the gross tumor volume (GTV) through the respiratory phases that constitute a four-dimensional computed tomography image data set. Methods and Materials: Four-dimensional computed tomography data sets of 20 patients who had undergone definitive hypofractionated radiotherapy to the lung were acquired. The GTV regions of interest (ROIs) were manually delineated on each phase of the four-dimensional computed tomography data set. The ROI from the end-expiration phase was propagated to the remaining nine phases of respiration using the following three techniques: (1) rigid-image registration using in-house software, (2) rigid image registration using research software from a commercial radiotherapy planning system vendor, and (3) rigid-image registration followed by deformable adaptation originally intended for organ-at-risk delineation using the same software. The internal GTVs generated from the various propagation methods were compared with the manual internal GTV using the normalized Dice similarity coefficient (DSC) index. Results: The normalized DSC index of 1.01 {+-} 0.06 (SD) for rigid propagation using the in-house software program was identical to the normalized DSC index of 1.01 {+-} 0.06 for rigid propagation achieved with the vendor's research software. Adaptive propagation yielded poorer results, with a normalized DSC index of 0.89 {+-} 0.10 (paired t test, p <0.001). Conclusion: Propagation of the GTV ROIs through the respiratory phases using rigid- body registration is an acceptable method within a 1-mm margin of uncertainty. The adaptive organ-at-risk propagation method was not applicable to propagating GTV ROIs, resulting in an unacceptable reduction of the volume and distortion of the ROIs.

Ezhil, Muthuveni [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)], E-mail: veniezhil@hotmail.com; Choi, Bum; Starkschall, George [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Bucci, M. Kara [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Vedam, Sastry; Balter, Peter [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2008-05-01T23:59:59.000Z

348

Computed tomography image using sub-terahertz waves generated from a high-T{sub c} superconducting intrinsic Josephson junction oscillator  

SciTech Connect (OSTI)

A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+?} was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications.

Kashiwagi, T., E-mail: kashiwagi@ims.tsukuba.ac.jp; Minami, H.; Kadowaki, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Nakade, K.; Saiwai, Y.; Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Shibano, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Tsujimoto, M. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Yamamoto, T. [Wide Bandgap Materials Group, Optical and Electronic Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Markovi?, B. [Faculty of Sciences, University of Montenegro, George Washington Str., 81000 Podgorica (Montenegro); Mirkovi?, J. [Faculty of Science, University of Montenegro, and CETI, Put Radomira Ivanovica, 81000 Podgorica (Montenegro); Klemm, R. A. [Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816-2385 (United States)

2014-02-24T23:59:59.000Z

349

A full-spectral Bayesian reconstruction approach based on the material decomposition model applied in dual-energy computed tomography  

SciTech Connect (OSTI)

Purpose: Dual-energy computed tomography (DECT) makes it possible to get two fractions of basis materials without segmentation. One is the soft-tissue equivalent water fraction and the other is the hard-matter equivalent bone fraction. Practical DECT measurements are usually obtained with polychromatic x-ray beams. Existing reconstruction approaches based on linear forward models without counting the beam polychromaticity fail to estimate the correct decomposition fractions and result in beam-hardening artifacts (BHA). The existing BHA correction approaches either need to refer to calibration measurements or suffer from the noise amplification caused by the negative-log preprocessing and the ill-conditioned water and bone separation problem. To overcome these problems, statistical DECT reconstruction approaches based on nonlinear forward models counting the beam polychromaticity show great potential for giving accurate fraction images.Methods: This work proposes a full-spectral Bayesian reconstruction approach which allows the reconstruction of high quality fraction images from ordinary polychromatic measurements. This approach is based on a Gaussian noise model with unknown variance assigned directly to the projections without taking negative-log. Referring to Bayesian inferences, the decomposition fractions and observation variance are estimated by using the joint maximum a posteriori (MAP) estimation method. Subject to an adaptive prior model assigned to the variance, the joint estimation problem is then simplified into a single estimation problem. It transforms the joint MAP estimation problem into a minimization problem with a nonquadratic cost function. To solve it, the use of a monotone conjugate gradient algorithm with suboptimal descent steps is proposed.Results: The performance of the proposed approach is analyzed with both simulated and experimental data. The results show that the proposed Bayesian approach is robust to noise and materials. It is also necessary to have the accurate spectrum information about the source-detector system. When dealing with experimental data, the spectrum can be predicted by a Monte Carlo simulator. For the materials between water and bone, less than 5% separation errors are observed on the estimated decomposition fractions.Conclusions: The proposed approach is a statistical reconstruction approach based on a nonlinear forward model counting the full beam polychromaticity and applied directly to the projections without taking negative-log. Compared to the approaches based on linear forward models and the BHA correction approaches, it has advantages in noise robustness and reconstruction accuracy.

Cai, C. [CEA, LIST, 91191 Gif-sur-Yvette, France and CNRS, SUPELEC, UNIV PARIS SUD, L2S, 3 rue Joliot-Curie, 91192 Gif-sur-Yvette (France)] [CEA, LIST, 91191 Gif-sur-Yvette, France and CNRS, SUPELEC, UNIV PARIS SUD, L2S, 3 rue Joliot-Curie, 91192 Gif-sur-Yvette (France); Rodet, T.; Mohammad-Djafari, A. [CNRS, SUPELEC, UNIV PARIS SUD, L2S, 3 rue Joliot-Curie, 91192 Gif-sur-Yvette (France)] [CNRS, SUPELEC, UNIV PARIS SUD, L2S, 3 rue Joliot-Curie, 91192 Gif-sur-Yvette (France); Legoupil, S. [CEA, LIST, 91191 Gif-sur-Yvette (France)] [CEA, LIST, 91191 Gif-sur-Yvette (France)

2013-11-15T23:59:59.000Z

350

Predicting oropharyngeal tumor volume throughout the course of radiation therapy from pretreatment computed tomography data using general linear models  

SciTech Connect (OSTI)

Purpose: The purpose of this work was to develop and evaluate the accuracy of several predictive models of variation in tumor volume throughout the course of radiation therapy. Methods: Nineteen patients with oropharyngeal cancers were imaged daily with CT-on-rails for image-guided alignment per an institutional protocol. The daily volumes of 35 tumors in these 19 patients were determined and used to generate (1) a linear model in which tumor volume changed at a constant rate, (2) a general linear model that utilized the power fit relationship between the daily and initial tumor volumes, and (3) a functional general linear model that identified and exploited the primary modes of variation between time series describing the changing tumor volumes. Primary and nodal tumor volumes were examined separately. The accuracy of these models in predicting daily tumor volumes were compared with those of static and linear reference models using leave-one-out cross-validation. Results: In predicting the daily volume of primary tumors, the general linear model and the functional general linear model were more accurate than the static reference model by 9.9% (range: ?11.6%–23.8%) and 14.6% (range: ?7.3%–27.5%), respectively, and were more accurate than the linear reference model by 14.2% (range: ?6.8%–40.3%) and 13.1% (range: ?1.5%–52.5%), respectively. In predicting the daily volume of nodal tumors, only the 14.4% (range: ?11.1%–20.5%) improvement in accuracy of the functional general linear model compared to the static reference model was statistically significant. Conclusions: A general linear model and a functional general linear model trained on data from a small population of patients can predict the primary tumor volume throughout the course of radiation therapy with greater accuracy than standard reference models. These more accurate models may increase the prognostic value of information about the tumor garnered from pretreatment computed tomography images and facilitate improved treatment management.

Yock, Adam D., E-mail: ADYock@mdanderson.org; Kudchadker, Rajat J. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States); Rao, Arvind [Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and the Graduate School of Biomedical Sciences, the University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and the Graduate School of Biomedical Sciences, the University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States); Dong, Lei [Scripps Proton Therapy Center, San Diego, California 92121 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Scripps Proton Therapy Center, San Diego, California 92121 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States); Beadle, Beth M.; Garden, Adam S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)] [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Court, Laurence E. [Department of Radiation Physics and Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Department of Radiation Physics and Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)

2014-05-15T23:59:59.000Z

351

Comparison of x ray computed tomography number to proton relative linear stopping power conversion functions using a standard phantom  

SciTech Connect (OSTI)

Purpose: Adequate evaluation of the results from multi-institutional trials involving light ion beam treatments requires consideration of the planning margins applied to both targets and organs at risk. A major uncertainty that affects the size of these margins is the conversion of x ray computed tomography numbers (XCTNs) to relative linear stopping powers (RLSPs). Various facilities engaged in multi-institutional clinical trials involving proton beams have been applying significantly different margins in their patient planning. This study was performed to determine the variance in the conversion functions used at proton facilities in the U.S.A. wishing to participate in National Cancer Institute sponsored clinical trials. Methods: A simplified method of determining the conversion function was developed using a standard phantom containing only water and aluminum. The new method was based on the premise that all scanners have their XCTNs for air and water calibrated daily to constant values but that the XCTNs for high density/high atomic number materials are variable with different scanning conditions. The standard phantom was taken to 10 different proton facilities and scanned with the local protocols resulting in 14 derived conversion functions which were compared to the conversion functions used at the local facilities. Results: For tissues within ±300 XCTN of water, all facility functions produced converted RLSP values within ±6% of the values produced by the standard function and within 8% of the values from any other facility's function. For XCTNs corresponding to lung tissue, converted RLSP values differed by as great as ±8% from the standard and up to 16% from the values of other facilities. For XCTNs corresponding to low-density immobilization foam, the maximum to minimum values differed by as much as 40%. Conclusions: The new method greatly simplifies determination of the conversion function, reduces ambiguity, and in the future could promote standardization between facilities. Although it was not possible from these experiments to determine which conversion function is most appropriate, the variation between facilities suggests that the margins used in some facilities to account for the uncertainty in converting XCTNs to RLSPs may be too small.

Moyers, M. F., E-mail: MFMoyers@roadrunner.com [Shanghai Proton and Heavy Ion Center, Shanghai, China 201321 (China)

2014-06-15T23:59:59.000Z

352

A quality assurance framework for the fully automated and objective evaluation of image quality in cone-beam computed tomography  

SciTech Connect (OSTI)

Purpose: Thousands of cone-beam computed tomography (CBCT) scanners for vascular, maxillofacial, neurological, and body imaging are in clinical use today, but there is no consensus on uniform acceptance and constancy testing for image quality (IQ) and dose yet. The authors developed a quality assurance (QA) framework for fully automated and time-efficient performance evaluation of these systems. In addition, the dependence of objective Fourier-based IQ metrics on direction and position in 3D volumes was investigated for CBCT. Methods: The authors designed a dedicated QA phantom 10 cm in length consisting of five compartments, each with a diameter of 10 cm, and an optional extension ring 16 cm in diameter. A homogeneous section of water-equivalent material allows measuring CT value accuracy, image noise and uniformity, and multidimensional global and local noise power spectra (NPS). For the quantitative determination of 3D high-contrast spatial resolution, the modulation transfer function (MTF) of centrally and peripherally positioned aluminum spheres was computed from edge profiles. Additional in-plane and axial resolution patterns were used to assess resolution qualitatively. The characterization of low-contrast detectability as well as CT value linearity and artifact behavior was tested by utilizing sections with soft-tissue-equivalent and metallic inserts. For an automated QA procedure, a phantom detection algorithm was implemented. All tests used in the dedicated QA program were initially verified in simulation studies and experimentally confirmed on a clinical dental CBCT system. Results: The automated IQ evaluation of volume data sets of the dental CBCT system was achieved with the proposed phantom requiring only one scan for the determination of all desired parameters. Typically, less than 5 min were needed for phantom set-up, scanning, and data analysis. Quantitative evaluation of system performance over time by comparison to previous examinations was also verified. The maximum percentage interscan variation of repeated measurements was less than 4% and 1.7% on average for all investigated quality criteria. The NPS-based image noise differed by less than 5% from the conventional standard deviation approach and spatially selective 10% MTF values were well comparable to subjective results obtained with 3D resolution pattern. Determining only transverse spatial resolution and global noise behavior in the central field of measurement turned out to be insufficient. Conclusions: The proposed framework transfers QA routines employed in conventional CT in an advanced version to CBCT for fully automated and time-efficient evaluation of technical equipment. With the modular phantom design, a routine as well as an expert version for assessing IQ is provided. The QA program can be used for arbitrary CT units to evaluate 3D imaging characteristics automatically.

Steiding, Christian; Kolditz, Daniel; Kalender, Willi A., E-mail: willi.kalender@imp.uni-erlangen.de [Institute of Medical Physics, University of Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany and CT Imaging GmbH, 91052 Erlangen (Germany)

2014-03-15T23:59:59.000Z

353

Use of 4-Dimensional Computed Tomography-Based Ventilation Imaging to Correlate Lung Dose and Function With Clinical Outcomes  

SciTech Connect (OSTI)

Purpose: Four-dimensional computed tomography (4DCT)-based ventilation is an emerging imaging modality that can be used in the thoracic treatment planning process. The clinical benefit of using ventilation images in radiation treatment plans remains to be tested. The purpose of the current work was to test the potential benefit of using ventilation in treatment planning by evaluating whether dose to highly ventilated regions of the lung resulted in increased incidence of clinical toxicity. Methods and Materials: Pretreatment 4DCT data were used to compute pretreatment ventilation images for 96 lung cancer patients. Ventilation images were calculated using 4DCT data, deformable image registration, and a density-change based algorithm. Dose–volume and ventilation-based dose function metrics were computed for each patient. The ability of the dose–volume and ventilation-based dose–function metrics to predict for severe (grade 3+) radiation pneumonitis was assessed using logistic regression analysis, area under the curve (AUC) metrics, and bootstrap methods. Results: A specific patient example is presented that demonstrates how incorporating ventilation-based functional information can help separate patients with and without toxicity. The logistic regression significance values were all lower for the dose–function metrics (range P=.093-.250) than for their dose–volume equivalents (range, P=.331-.580). The AUC values were all greater for the dose–function metrics (range, 0.569-0.620) than for their dose–volume equivalents (range, 0.500-0.544). Bootstrap results revealed an improvement in model fit using dose–function metrics compared to dose–volume metrics that approached significance (range, P=.118-.155). Conclusions: To our knowledge, this is the first study that attempts to correlate lung dose and 4DCT ventilation-based function to thoracic toxicity after radiation therapy. Although the results were not significant at the .05 level, our data suggests that incorporating ventilation-based functional imaging can improve prediction for radiation pneumonitis. We present an important first step toward validating the use of 4DCT-based ventilation imaging in thoracic treatment planning.

Vinogradskiy, Yevgeniy, E-mail: yevgeniy.vinogradskiy@ucdenver.edu [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States); Castillo, Richard [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Castillo, Edward [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States) [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Computational and Applied Mathematics, Rice University, Houston, Texas (United States); Tucker, Susan L. [Departments of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Departments of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao, Zhongxing [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Guerrero, Thomas [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States) [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Computational and Applied Mathematics, Rice University, Houston, Texas (United States); Martel, Mary K. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2013-06-01T23:59:59.000Z

354

X-ray micro-tomography investigation of the foaming process in the system of waste glass–silica mud–MnO{sub 2}  

SciTech Connect (OSTI)

In case of foamed lightweight aggregates (LWAs), porosity is introduced by the addition of a foaming agent to the glassy matrix, which degasses at an elevated temperature, so that the resulting gases remain trapped inside the glassy structure. The efficiency of action of MnO{sub 2} as a foaming agent in waste glass and waste glass/silica mud systems was studied. Samples were fired at different temperatures and with different dwelling times at a certain temperature, and the development of porosity was investigated by means of X-ray micro-tomography. It was found that, with the prolongation in dwelling times, the number of pores decreased, while, on the other hand, the volume of these pores increased, and that the addition of silica mud increases the foaming temperature and slows down the foaming process. - Highlights: • Preparation of lightweight aggregate from waste glass, silica sludge, and MnO{sub 2} • DTA/TG investigation of MnO{sub 2} • Characterization of pore-forming process by means of X-ray micro-tomography (?cT)

Ducman, V., E-mail: vilma.ducman@zag.si [ZAG Ljubljana, Dimi?eva 12, 1000 Ljubljana (Slovenia); Korat, L.; Legat, A. [ZAG Ljubljana, Dimi?eva 12, 1000 Ljubljana (Slovenia); Mirti?, B. [NTF, Ašker?eva 12, 1000 Ljubljana (Slovenia)

2013-12-15T23:59:59.000Z

355

Understanding Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Microscopy and Field Evaporation Simulation  

SciTech Connect (OSTI)

Metal-dielectric composite materials, specifically metal nanoparticles supported on or embedded in metal oxides, are widely used in catalysis. The accurate optimization of such nanostructures warrants the need for detailed three-dimensional characterization. Atom probe tomography is uniquely capable of generating sub-nanometer structural and compositional data with part-per-million mass sensitivity, but there are reconstruction artifacts for composites containing materials with strongly differing fields of evaporation, as for oxide-supported metal nanoparticles. By correlating atom probe tomography with scanning transmission electron microscopy for Au nanoparticles embedded in an MgO support, deviations from an ideal topography during evaporation are demonstrated directly, and correlated with compositional errors in the reconstructed data. Finite element simulations of the field evaporation process confirm that protruding Au nanoparticles will evolve on the tip surface, and that evaporation field variations lead to an inaccurate assessment of the local composition, effectively lowering the spatial resolution of the final reconstructed dataset. Cross-correlating the experimental data with simulations results in a more detailed understanding of local evaporation aberrations during APT analysis of metal-oxide composites, paving the way towards a more accurate three-dimensional characterization of this technologically important class of materials.

Devaraj, Arun; Colby, Robert J.; Vurpillot, F.; Thevuthasan, Suntharampillai

2014-03-26T23:59:59.000Z

356

Apparatus and method for preparing oxygen-15 labeled water H{sub 2}[{sup 15}O] in an injectable form for use in positron emission tomography  

DOE Patents [OSTI]

A handling and processing apparatus is revealed for preparing Oxygen-15 labeled water (H{sub 2}[{sup 15}O]) in injectable form for use in Positron Emission Tomography from preferably H{sub 2}[{sup 15}O] produced by irradiating a flowing gas target of nitrogen and hydrogen. The apparatus includes a collector for receiving and directing a gas containing H{sub 2}[{sup 15}O] gas and impurities, mainly ammonia (NH{sub 3}) gas into sterile water to trap the H{sub 2}[{sup 15}O] and form ammonium (NH{sub 4}{sup +}) in the sterile water. A device for displacing the sterile water containing H{sub 2}[{sup 15}O] and NH{sub 4}{sup +} through a cation resin removes NH{sub 4}{sup +} from the sterile water. A device for combining the sterile water containing H{sub 2}[{sup 15}O] with a saline solution produces an injectable solution. Preferably, the apparatus includes a device for delivering the solution to a syringe for injection into a patient. Also, disclosed is a method for preparing H{sub 2}[{sup 15}O] in injectable form for use in Positron Emission Tomography in which the method neither requires isotopic exchange reaction nor application of high temperature. 7 figs.

Ferrieri, R.A.; Schlyer, D.J.; Alexoff, D.

1996-01-09T23:59:59.000Z

357

Apparatus and method for preparing oxygen-15 labeled water H.sub.2 [.sup.15 O] in an injectable form for use in positron emission tomography  

DOE Patents [OSTI]

A handling and processing apparatus for preparing Oxygen-15 labeled water (H.sub.2 [.sup.15 O]) in injectable form for use in Positron Emission Tomography from preferably H.sub.2 [.sup.15 O] produced by irradiating a flowing gas target of nitrogen and hydrogen. The apparatus includes a collector for receiving and directing a gas containing H.sub.2 [.sup.15 O] gas and impurities, mainly ammonia (NH.sub.3) gas into sterile water to trap the H.sub.2 [.sup.15 O] and form ammonium (NH.sub.4.sup.+) in the sterile water. A device for displacing the sterile water containing H.sub.2 [.sup.15 O] and NH.sub.4.sup.+ through a cation resin removes NH.sub.4.sup.+ from the sterile water. A device for combining the sterile water containing H.sub.2 [.sup.15 O] with a saline solution produces an injectable solution. Preferably, the apparatus includes a device for delivering the solution to a syringe for injection into a patient. Also, disclosed is a method for preparing H.sub.2 [.sup.15 O] in injectable form for use in Positron Emission Tomography in which the method neither requires isotopic exchange reaction nor application of high temperature.

Ferrieri, Richard A. (Patchogue, NY); Schlyer, David J. (Bellport, NY); Alexoff, David (Westhampton, NY)

1996-01-09T23:59:59.000Z

358

Neutron wave packet tomography  

E-Print Network [OSTI]

A tomographic technique is introduced in order to determine the quantum state of the center of mass motion of neutrons. An experiment is proposed and numerically analyzed.

G. Badurek; P. Facchi; Y. Hasegawa; Z. Hradil; S. Pascazio; H. Rauch; J. Rehacek; T. Yoneda

2005-03-29T23:59:59.000Z

359

Atom Probe Tomography | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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360

Muon Muon Collider: Feasibility Study  

SciTech Connect (OSTI)

A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle reactions which are open to a muon collider and the physics of such reactions - what one learns and the necessary luminosity to see interesting events - are described in detail. Most of the physics accesible to an e{sup +} - e{sup -} collider could be studied in a muon collider. In addition the production of Higgs bosons in the s-channel will allow the measurement of Higgs masses and total widths to high precision; likewise, t{bar t} and W{sup +}W{sup -} threshold studies would yield m{sub t} and m{sub w} to great accuracy. These reactions are at low center of mass energy (if the MSSM is correct) and the luminosity and {Delta}p/p of the beams required for these measurements is detailed in the Physics Chapter. On the other hand, at 2 + 2 TeV, a luminosity of L {approx} 10{sup 35} cm{sup -2}s{sup -1} is desirable for studies such as, the scattering of longitudinal W bosons or the production of heavy scalar particles. Not explored in this work, but worth noting, are the opportunities for muon-proton and muon-heavy ion collisions as well as the enormous richness of such a facility for fixed target physics provided by the intense beams of neutrinos, muons, pions, kaons, antiprotons and spallation neutrons. To see all the interesting physics described herein requires a careful study of the operation of a detector in the very large background. Three sources of background have been identified. The first is from any halo accompanying the muon beams in the collider ring. Very carefully prepared beams will have to be injected and maintained. The second is due to the fact that on average 35% of the muon energy appears in its decay electron. The energy of the electron subsequently is converted into EM showers either from the synchrotron radiation they emit in the collider magnetic field or from direct collision with the surrounding material. The decays that occur as the beams traverse the low beta insert are of particular concern for detector backgrounds. A third source of background is e{sup +} - e{sup -} pair creation from {mu}{sup +} - {mu}{sup -} interaction. Studies of

Gallardo, J.C.; Palmer, R.B.; /Brookhaven; Tollestrup, A.V.; /Fermilab; Sessler, A.M.; /LBL, Berkeley; Skrinsky, A.N.; /Novosibirsk, IYF; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley; ,

2012-04-05T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
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361

Thoracic target volume delineation using various maximum-intensity projection computed tomography image sets for radiotherapy treatment planning  

SciTech Connect (OSTI)

Purpose: Four-dimensional computed tomography (4D-CT) is commonly used to account for respiratory motion of target volumes in radiotherapy to the thorax. From the 4D-CT acquisition, a maximum-intensity projection (MIP) image set can be created and used to help define the tumor motion envelope or the internal gross tumor volume (iGTV). The purpose of this study was to quantify the differences in automatically contoured target volumes for usage in the delivery of stereotactic body radiation therapy using MIP data sets generated from one of the four methods: (1) 4D-CT phase-binned (PB) based on retrospective phase calculations, (2) 4D-CT phase-corrected phase-binned (PC-PB) based on motion extrema, (3) 4D-CT amplitude-binned (AB), and (4) cine CT built from all available images. Methods: MIP image data sets using each of the four methods were generated for a cohort of 28 patients who had prior thoracic 4D-CT scans that exhibited lung tumor motion of at least 1 cm. Each MIP image set was automatically contoured on commercial radiation treatment planning system. Margins were added to the iGTV to observe differences in the final simulated planning target volumes (PTVs). Results: For all patients, the iGTV measured on the MIP generated from the entire cine CT data set (iGTV{sub cine}) was the largest. Expressed as a percentage of iGTV{sub cine}, 4D-CT iGTV (all sorting methods) ranged from 83.8% to 99.1%, representing differences in the absolute volume ranging from 0.02 to 4.20 cm{sup 3}; the largest average and range of 4D-CT iGTV measurements was from the PC-PB data set. Expressed as a percentage of PTV{sub cine} (expansions applied to iGTV{sub cine}), the 4D-CT PTV ranged from 87.6% to 99.6%, representing differences in the absolute volume ranging from 0.08 to 7.42 cm{sup 3}. Regions of the measured respiratory waveform corresponding to a rapid change of phase or amplitude showed an increased susceptibility to the selection of identical images for adjacent bins. Duplicate image selection was most common in the AB implementation, followed by the PC-PB method. The authors also found that the image associated with the minimum amplitude measurement did not always correlate with the image that showed maximum tumor motion extent. Conclusions: The authors identified cases in which the MIP generated from a 4D-CT sorting process under-represented the iGTV by more than 10% or up to 4.2 cm{sup 3} when compared to the iGTV{sub cine}. They suggest utilization of a MIP generated from the full cine CT data set to ensure maximum inclusive tumor extent.

Zamora, David A.; Riegel, Adam C.; Sun Xiaojun; Balter, Peter; Starkschall, George; Mawlawi, Osama; Pan Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2010-11-15T23:59:59.000Z

362

Breaking the Crowther Limit: Combining Depth-Sectioning and Tilt Tomography for High-Resolution, Wide-Field 3D Reconstructions  

E-Print Network [OSTI]

To date, high-resolution ( 6 nm) to appear blurred or missing. Here we demonstrate a three-dimensional imaging method that overcomes both these limits by combining through-focal depth sectioning and traditional tilt-series tomography to reconstruct extended objects, with high-resolution, in all three dimensions. The large convergence angle in aberration corrected instruments now becomes a benefit and not a hindrance to higher quality reconstructions. A through-focal reconstruction over a 390 nm 3D carbon support containing over one hundred dealloyed and nanoporous PtCu catalyst particles revealed with sub-nanometer detail the extensive and connected interior pore structure that is created by the dealloying instability.

Hovden, Robert; Jiang, Yi; Wang, Deli; Yu, Yingchao; Abruna, Hector D; Elser, Veit; Muller, David A

2014-01-01T23:59:59.000Z

363

Multispectral breast imaging using a ten-wavelength, 64x64 source/detector channels silicon photodiode-based diffuse optical tomography system  

SciTech Connect (OSTI)

We describe a compact diffuse optical tomography system specifically designed for breast imaging. The system consists of 64 silicon photodiode detectors, 64 excitation points, and 10 diode lasers in the near-infrared region, allowing multispectral, three-dimensional optical imaging of breast tissue. We also detail the system performance and optimization through a calibration procedure. The system is evaluated using tissue-like phantom experiments and an in vivo clinic experiment. Quantitative two-dimensional (2D) and three-dimensional (3D) images of absorption and reduced scattering coefficients are obtained from these experiments. The ten-wavelength spectra of the extracted reduced scattering coefficient enable quantitative morphological images to be reconstructed with this system. From the in vivo clinic experiment, functional images including deoxyhemoglobin, oxyhemoglobin, and water concentration are recovered and tumors are detected with correct size and position compared with the mammography.

Li Changqing; Zhao Hongzhi; Anderson, Bonnie; Jiang Huabei [Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 (United States); Department of Radiology, Oconee Memorial Hospital, Seneca, South Carolina 29672 (United States); Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 (United States)

2006-03-15T23:59:59.000Z

364

Roche tomography of cataclysmic variables -- II. Images of the secondary stars in AM Her, QQ Vul, IP Peg and HU Aqr  

E-Print Network [OSTI]

We present a set of Roche tomography reconstructions of the secondary stars in the cataclysmic variables AM Her, QQ Vul, IP Peg and HU Aqr. The image reconstructions show distinct asymmetries in the irradiation pattern for all four systems which can be attributed to shielding of the secondary star by the accretion stream/column in AM Her, QQ Vul and HU Aqr, and increased irradiation by the bright spot in IP Peg. We use the entropy landscape technique to derive accurate system parameters (M1, M2, i and gamma) for the four binaries. In principle, this technique should provide the most reliable mass determinations available, since the intensity distribution across the secondary star is known. We also find that the intensity distribution can systematically affect the value of gamma derived from circular orbit fits to radial velocity variations.

C. A. Watson; V. S. Dhillon; R. G. M. Rutten; A. D. Schwope

2003-02-06T23:59:59.000Z

365

Improving Soft-Tissue Contrast in Four-Dimensional Computed Tomography Images of Liver Cancer Patients Using a Deformable Image Registration Method  

SciTech Connect (OSTI)

Purpose: To investigate a deformable image registration method to improve soft-tissue contrast in four-dimensional (4D) computed tomography (CT) images of the liver. Methods and Materials: Ten patients with hepatocellular carcinoma underwent 4D CT scan for radiotherapy treatment planning on a positron emission tomography/CT scanner. Four-dimensional CT images were binned into 10 equispaced phases. The exhale phase served as the reference phase, and images from the other nine phases were coregistered to the reference phase image using an intensity-based, automatic deformable image registration method. Then the coregistered images were combined to create a single, high-quality reconstructed CT image at exhale phase as the new reference for target delineation. The extent of image quality enhancement was quantified relative to the original CT by calculating the signal-to-noise ratio and the contrast-to-noise ratio. Results: The soft tissue image contrast was noticeably better after deformable image registration than in the original scans. Signal-to-noise ratios inside the liver region of interest increased for all patients by a factor of 3.0 (range, 2.3-3.7). The improvement in image quality was not linearly proportionate to the number of images averaged. Using only 6 phases can achieve at least 85% of the contrast enhancement that can be achieved using all 10 phases. We also found that contrast enhancement was inversely proportional to the original image quality (p = 0.006), and the contrast enhancement is attained with little loss of spatial resolution. Conclusions: This deformable image registration method is feasible to improve soft-tissue image quality in 4D CT images.

Wang He [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Krishnan, Sunil [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Wang Xiaochun; Beddar, A. Sam; Briere, Tina M. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Crane, Christopher H. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Dong Lei [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)], E-mail: ldong@mdanderson.org

2008-09-01T23:59:59.000Z

366

A study on planning organ at risk volume for the rectum using cone beam computed tomography in the treatment of prostate cancer  

SciTech Connect (OSTI)

In this study, we analyzed planning organ at risk volume (PRV) for the rectum using a series of cone beam computed tomographies (CBCTs) acquired during the treatment of prostate cancer and evaluated the dosimetric effect of different PRV definitions. Overall, 21 patients with prostate cancer were treated radically with 78 Gy in 39 fractions had in total 418 CBCTs, each acquired at the end of the first 5 fractions and then every alternate fraction. The PRV was generated from the Boolean sum volume of the rectum obtained from first 5 fractions (PRV-CBCT-5) and from all CBCTs (PRV-CBCT-All). The PRV margin was compared at the superior, middle, and inferior slices of the contoured rectum to compare PRV-CBCT-5 and PRV-CBCT-All. We also compared the dose received by the planned rectum (Rectum-computed tomography [CT]), PRV-CBCT-5, PRV-CBCT-All, and average rectum (CBCT-AV-dose-volume histogram [DVH]) at critical dose levels. The average measured rectal volume for all 21 patients for Rectum-CT, PRV-CBCT-5, and PRV-CBCT-All was 44.3 ± 15.0, 92.8 ± 40.40, and 121.5 ± 36.7 cm{sup 3}, respectively. For PRV-CBCT-All, the mean ± standard deviation displacement in the anterior, posterior, right, and left lateral directions in centimeters was 2.1 ± 1.1, 0.9 ± 0.5, 0.9 ± 0.8, and 1.1 ± 0.7 for the superior rectum; 0.8 ± 0.5, 1.1 ± 0.5, 1.0 ± 0.5, and 1.0 ± 0.5 for the middle rectum; and 0.3 ± 0.3; 0.9 ± 0.5; 0.4 ± 0.2, and 0.5 ± 0.3 for the inferior rectum, respectively. The first 5 CBCTs did not predict the PRV for individual patients. Our study shows that the PRV margin is different for superior, middle, and the inferior parts of the rectum, it is wider superiorly and narrower inferiorly. A uniform PRV margin does not represent the actual rectal variations during treatment for all treatment fractions. The large variation in interpatient rectal size implies a potential role for adaptive radiotherapy for prostate cancer.

Prabhakar, Ramachandran, E-mail: Ramachandran.Prabhakar@petermac.org [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); RMIT University, Melbourne (Australia); Oates, Richard; Jones, Daryl [Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne (Australia); Kron, Tomas [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); RMIT University, Melbourne (Australia); Cramb, Jim [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Foroudi, Farshad [Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne (Australia); Geso, Moshi [RMIT University, Melbourne (Australia); Gill, Suki [Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne (Australia)

2014-04-01T23:59:59.000Z

367

Application of x-ray tomography to optimization of new NOx/NH3 mixed potential sensors for vehicle on-board emissions control  

SciTech Connect (OSTI)

Mixed potential sensors for the detection of hydrocarbons, NO{sub x}, and NH{sub 3} have been previously developed at Los Alamos National Laboratory (LANL). The LANL sensors have a unique design incorporating dense ceramic-pelletlmetal-wire electrodes and porous electrolytes. The performance of current-biased sensors using an yttria-stabilized zirconia (YSZ) electrolyte and platinum and La{sub 0.8}Sr{sub 0.2}CrO{sub 3} electrodes is reported. X-ray tomography has been applied to non-destructively examine internal structures of these sensors. NO{sub x} and hydrocarbon response of the sensors under various bias conditions is reported, and very little NO{sub x} response hysteresis was observed. The application of a 0.6 {mu}A bias to these sensors shifts the response from a hydrocarbon response to a NO{sub x} response equal for both NO and NO{sub 2} species at approximately 500 {sup o}C in air.

Nelson, Mark A [Los Alamos National Laboratory; Brosha, Eric L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Garzon, Fernando H [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

368

Ultrasound guided fluorescence molecular tomography with improved quantification by an attenuation compensated born-normalization and in vivo preclinical study of cancer  

SciTech Connect (OSTI)

Ultrasound imaging, having the advantages of low-cost and non-invasiveness over MRI and X-ray CT, was reported by several studies as an adequate complement to fluorescence molecular tomography with the perspective of improving localization and quantification of fluorescent molecular targets in vivo. Based on the previous work, an improved dual-modality Fluorescence-Ultrasound imaging system was developed and then validated in imaging study with preclinical tumor model. Ultrasound imaging and a profilometer were used to obtain the anatomical prior information and 3D surface, separately, to precisely extract the tissue boundary on both sides of sample in order to achieve improved fluorescence reconstruction. Furthermore, a pattern-based fluorescence reconstruction on the detection side was incorporated to enable dimensional reduction of the dataset while keeping the useful information for reconstruction. Due to its putative role in the current imaging geometry and the chosen reconstruction technique, we developed an attenuation compensated Born-normalization method to reduce the attenuation effects and cancel off experimental factors when collecting quantitative fluorescence datasets over large area. Results of both simulation and phantom study demonstrated that fluorescent targets could be recovered accurately and quantitatively using this reconstruction mechanism. Finally, in vivo experiment confirms that the imaging system associated with the proposed image reconstruction approach was able to extract both functional and anatomical information, thereby improving quantification and localization of molecular targets.

Li, Baoqiang; Berti, Romain; Abran, Maxime; Lesage, Frédéric, E-mail: frederic.lesage@polymtl.ca [Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7 (Canada) [Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7 (Canada); Montreal Heart Institute, Montreal, Quebec H1T 1C8 (Canada)

2014-05-15T23:59:59.000Z

369

Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?  

SciTech Connect (OSTI)

PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.

Wagner, Marlies, E-mail: marlies.wagner@kgu.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Kyriakou, Yiannis, E-mail: yiannis.kyriakou@siemens.com [Siemens AG, Health Care Sector (Germany); Mesnil de Rochemont, Richard du, E-mail: mesnil@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Singer, Oliver C., E-mail: o.singer@em.uni-frankfurt.de [Hospital of Goethe University, Department of Neurology (Germany); Berkefeld, Joachim, E-mail: berkefeld@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany)

2013-08-01T23:59:59.000Z

370

Microaspiration for high-pressure freezing: a new method for ultrastructural preservation of fragile and sparse tissues for TEM and electron tomography  

SciTech Connect (OSTI)

High-pressure freezing is the preferred method to prepare thick biological specimens for ultrastructural studies. However, the advantages obtained by this method often prove unattainable for samples that are difficult to handle during the freezing and substitution protocols. Delicate and sparse samples are difficult to manipulate and maintain intact throughout the sequence of freezing, infiltration, embedding, and final orientation for sectioning and subsequent TEM imaging. An established approach to surmount these difficulties is the use of cellulose microdialysis tubing to transport the sample. With an inner diameter of 200 micrometers, the tubing protects small and fragile samples within the thickness constraints of high-pressure freezing, and the tube ends can be sealed to avoid loss of sample. Importantly, the transparency of the tubing allows optical study of the specimen at different steps in the process. Here, we describe the use of a micromanipulator and microinjection apparatus to handle and position delicate specimens within the tubing. We report two biologically significant examples that benefit from this approach, 3D cultures of mammary epithelial cells and cochlear outer hair cells. We illustrate the potential for correlative light and electron microscopy as well as electron tomography.

Auer, Manfred; Triffo, W.J.; Palsdottir, H.; McDonald, K.L.; Inman, J.L.; Bissell, M.J.; Raphael, R.M.; Auer, M.; Lee, J.K.

2008-02-13T23:59:59.000Z

371

Nanoscale Phase Separation In Epitaxial Cr-Mo and Cr-V Alloy Thin Films Studied Using Atom Probe Tomography: Comparison Of Experiments And Simulation  

SciTech Connect (OSTI)

Tailored metal alloy thin film-oxide interfaces generated using molecular beam epitaxial (MBE) deposition of alloy thin films on a single crystalline oxide substrate can be used for detailed studies of irradiation damage response on the interface structure. However presence of nanoscale phase separation in the MBE grown alloy thin films can impact the metal-oxide interface structure. Due to nanoscale domain size of such phase separation it is very challenging to characterize by conventional techniques. Therefor laser assisted atom probe tomography (APT) was utilized to study the phase separation in epitaxial Cr0.61Mo0.39, Cr0.77Mo0.23, and Cr0.32V0.68 alloy thin films grown by MBE on MgO(001) single crystal substrates. Statistical analysis, namely frequency distribution analysis and Pearson coefficient analysis of experimental data was compared with similar analyses conducted on simulated APT datasets with known extent of phase separation. Thus the presence of phase separation in Cr-Mo films, even when phase separation was not clearly observed by x-ray diffraction, and the absence of phase separation in the Cr-V film were thus confirmed.

Devaraj, Arun; Kaspar, Tiffany C.; Ramanan, Sathvik; Walvekar, Sarita K.; Bowden, Mark E.; Shutthanandan, V.; Kurtz, Richard J.

2014-11-21T23:59:59.000Z

372

Comparison of Contrast-Enhanced Ultrasound and Computed Tomography in Classifying Endoleaks After Endovascular Treatment of Abdominal Aorta Aneurysms: Preliminary Experience  

SciTech Connect (OSTI)

The purpose of the study was to assess the effectiveness of contrast-enhanced ultrasonography (CEUS) in endoleak classification after endovascular treatment of an abdominal aortic aneurysm compared to computed tomography angiography (CTA). From May 2001 to April 2003, 10 patients with endoleaks already detected by CTA underwent CEUS with Sonovue (registered) to confirm the CTA classification or to reclassify the endoleak. In three conflicting cases, the patients were also studied with conventional angiography. CEUS confirmed the CTA classification in seven cases (type II endoleaks). Two CTA type III endoleaks were classified as type II using CEUS and one CTA type II endoleak was classified as type I by CEUS. Regarding the cases with discordant classification, conventional angiography confirmed the ultrasound classification. Additionally, CEUS documented the origin of type II endoleaks in all cases. After CEUS reclassification of endoleaks, a significant change in patient management occurred in three cases. CEUS allows a better attribution of the origin of the endoleak, as it shows the flow in real time. CEUS is more specific than CTA in endoleak classification and gives more accurate information in therapeutic planning.

Carrafiello, Gianpaolo, E-mail: gcarraf@tin.it; Lagana, Domenico; Recaldini, Chiara; Mangini, Monica; Bertolotti, Elena [University of Insubria, Department of Radiology (Italy); Caronno, Roberto; Tozzi, Matteo; Piffaretti, Gabriele [University of Insubria, Vascular Surgery (Italy); Annibale Genovese, Eugenio; Fugazzola, Carlo [University of Insubria, Department of Radiology (Italy)

2006-12-15T23:59:59.000Z

373

A 4D Synchrotron X-Ray-Tomography Study of the Formation of Hydrocarbon- Migration Pathways in Heated Organic-Rich Shale  

SciTech Connect (OSTI)

Recovery of oil from oil shales and the natural primary migration of hydrocarbons are closely related processes that have received renewed interest in recent years because of the ever tightening supply of conventional hydrocarbons and the growing production of hydrocarbons from low-permeability tight rocks. Quantitative models for conversion of kerogen into oil and gas and the timing of hydrocarbon generation have been well documented. However, lack of consensus about the kinetics of hydrocarbon formation in source rocks, expulsion timing, and how the resulting hydrocarbons escape from or are retained in the source rocks motivates further investigation. In particular, many mechanisms have been proposed for the transport of hydrocarbons from the rocks in which they are generated into adjacent rocks with higher permeabilities and smaller capillary entry pressures, and a better understanding of this complex process (primary migration) is needed. To characterize these processes, it is imperative to use the latest technological advances. In this study, it is shown how insights into hydrocarbon migration in source rocks can be obtained by using sequential high-resolution synchrotron X-ray tomography. Three-dimensional images of several immature "shale" samples were constructed at resolutions close to 5 um. This is sufficient to resolve the source-rock structure down to the grain level, but very-fine-grained silt particles, clay particles, and colloids cannot be resolved. Samples used in this investigation came from the R-8 unit in the upper part of the Green River shale, which is organic rich, varved, lacustrine marl formed in Eocene Lake Uinta, USA. One Green River shale sample was heated in situ up to 400 degrees C as X-ray-tomography images were recorded. The other samples were scanned before and after heating at 400 degrees C. During the heating phase, the organic matter was decomposed, and gas was released. Gas expulsion from the low-permeability shales was coupled with formation of microcracks. The main technical difficulty was numerical extraction of microcracks that have apertures in the 5- to 30-um range (with 5 um being the resolution limit) from a large 3D volume of X-ray attenuation data. The main goal of the work presented here is to develop a methodology to process these 3D data and image the cracks. This methodology is based on several levels of spatial filtering and automatic recognition of connected domains. Supportive petrographic and thermogravimetric data were an important complement to this study. An investigation of the strain field using 2D image correlation analyses was also performed. As one application of the 4D (space + time) microtomography and the developed workflow, we show that fluid generation was accompanied by crack formation. Under different conditions, in the subsurface, this might provide paths for primary migration.

Hamed Panahi; Paul Meakin; Francois Renard; Maya Kobchenko; Julien Scheibert; Adriano Mazzini; Bjorn Jamtveit; Anders Malthe-Sorenssen; Dag Kristian Dysthe

2013-04-01T23:59:59.000Z

374

Development and Clinical Evaluation of a Three-Dimensional Cone-Beam Computed Tomography Estimation Method Using a Deformation Field Map  

SciTech Connect (OSTI)

Purpose: To develop a three-dimensional (3D) cone-beam computed tomography (CBCT) estimation method using a deformation field map, and to evaluate and optimize the efficiency and accuracy of the method for use in the clinical setting. Methods and Materials: We propose a method to estimate patient CBCT images using prior information and a deformation model. Patients' previous CBCT data are used as the prior information, and the new CBCT volume to be estimated is considered as a deformation of the prior image volume. The deformation field map is solved by minimizing deformation energy and maintaining new projection data fidelity using a nonlinear conjugate gradient method. This method was implemented in 3D form using hardware acceleration and multi-resolution scheme, and it was evaluated for different scan angles, projection numbers, and scan directions using liver, lung, and prostate cancer patient data. The accuracy of the estimation was evaluated by comparing the organ volume difference and the similarity between estimated CBCT and the CBCT reconstructed from fully sampled projections. Results: Results showed that scan direction and number of projections do not have significant effects on the CBCT estimation accuracy. The total scan angle is the dominant factor affecting the accuracy of the CBCT estimation algorithm. Larger scan angles yield better estimation accuracy than smaller scan angles. Lung cancer patient data showed that the estimation error of the 3D lung tumor volume was reduced from 13.3% to 4.3% when the scan angle was increased from 60 Degree-Sign to 360 Degree-Sign using 57 projections. Conclusions: The proposed estimation method is applicable for 3D DTS, 3D CBCT, four-dimensional CBCT, and four-dimensional DTS image estimation. This method has the potential for significantly reducing the imaging dose and improving the image quality by removing the organ distortion artifacts and streak artifacts shown in images reconstructed by the conventional Feldkamp-Davis-Kress (FDK) algorithm.

Ren, Lei, E-mail: lren1@hfhs.org [Department of Radiation Oncology, Henry Ford Health System, Detroit, MI (United States); Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Health System, Detroit, MI (United States); Zhang Junan [Department of Radiation Oncology, Oregon Health and Science University, Portland, OR (United States); Jin Jianyue [Department of Radiation Oncology, Henry Ford Health System, Detroit, MI (United States); Wu, Q. Jackie; Yan Hui; Brizel, David M.; Lee, W. Robert [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Movsas, Benjamin [Department of Radiation Oncology, Henry Ford Health System, Detroit, MI (United States); Yin Fangfang [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

2012-04-01T23:59:59.000Z

375

Sample size requirements for estimating effective dose from computed tomography using solid-state metal-oxide-semiconductor field-effect transistor dosimetry  

SciTech Connect (OSTI)

Purpose: Effective dose (ED) is a widely used metric for comparing ionizing radiation burden between different imaging modalities, scanners, and scan protocols. In computed tomography (CT), ED can be estimated by performing scans on an anthropomorphic phantom in which metal-oxide-semiconductor field-effect transistor (MOSFET) solid-state dosimeters have been placed to enable organ dose measurements. Here a statistical framework is established to determine the sample size (number of scans) needed for estimating ED to a desired precision and confidence, for a particular scanner and scan protocol, subject to practical limitations. Methods: The statistical scheme involves solving equations which minimize the sample size required for estimating ED to desired precision and confidence. It is subject to a constrained variation of the estimated ED and solved using the Lagrange multiplier method. The scheme incorporates measurement variation introduced both by MOSFET calibration, and by variation in MOSFET readings between repeated CT scans. Sample size requirements are illustrated on cardiac, chest, and abdomen–pelvis CT scans performed on a 320-row scanner and chest CT performed on a 16-row scanner. Results: Sample sizes for estimating ED vary considerably between scanners and protocols. Sample size increases as the required precision or confidence is higher and also as the anticipated ED is lower. For example, for a helical chest protocol, for 95% confidence and 5% precision for the ED, 30 measurements are required on the 320-row scanner and 11 on the 16-row scanner when the anticipated ED is 4 mSv; these sample sizes are 5 and 2, respectively, when the anticipated ED is 10 mSv. Conclusions: Applying the suggested scheme, it was found that even at modest sample sizes, it is feasible to estimate ED with high precision and a high degree of confidence. As CT technology develops enabling ED to be lowered, more MOSFET measurements are needed to estimate ED with the same precision and confidence.

Trattner, Sigal [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Cheng, Bin [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States)] [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States); Pieniazek, Radoslaw L. [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)] [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Douglas, Pamela S. [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States)] [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States); Einstein, Andrew J., E-mail: andrew.einstein@columbia.edu [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York and Department of Radiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York (United States)

2014-04-15T23:59:59.000Z

376

Magnetoacoustic tomography with magnetic induction for high-resolution bioimepedance imaging through vector source reconstruction under the static field of MRI magnet  

SciTech Connect (OSTI)

Purpose: Magnetoacoustic tomography with magnetic induction (MAT-MI) is an imaging modality to reconstruct the electrical conductivity of biological tissue based on the acoustic measurements of Lorentz force induced tissue vibration. This study presents the feasibility of the authors' new MAT-MI system and vector source imaging algorithm to perform a complete reconstruction of the conductivity distribution of real biological tissues with ultrasound spatial resolution. Methods: In the present study, using ultrasound beamformation, imaging point spread functions are designed to reconstruct the induced vector source in the object which is used to estimate the object conductivity distribution. Both numerical studies and phantom experiments are performed to demonstrate the merits of the proposed method. Also, through the numerical simulations, the full width half maximum of the imaging point spread function is calculated to estimate of the spatial resolution. The tissue phantom experiments are performed with a MAT-MI imaging system in the static field of a 9.4 T magnetic resonance imaging magnet. Results: The image reconstruction through vector beamformation in the numerical and experimental studies gives a reliable estimate of the conductivity distribution in the object with a ?1.5 mm spatial resolution corresponding to the imaging system frequency of 500 kHz ultrasound. In addition, the experiment results suggest that MAT-MI under high static magnetic field environment is able to reconstruct images of tissue-mimicking gel phantoms and real tissue samples with reliable conductivity contrast. Conclusions: The results demonstrate that MAT-MI is able to image the electrical conductivity properties of biological tissues with better than 2 mm spatial resolution at 500 kHz, and the imaging with MAT-MI under a high static magnetic field environment is able to provide improved imaging contrast for biological tissue conductivity reconstruction.

Mariappan, Leo; Hu, Gang [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 (United States)] [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 (United States); He, Bin, E-mail: binhe@umn.edu [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 and Institute of Engineering in Medicine, University of Minnesota, Minnesota 55455 (United States)] [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 and Institute of Engineering in Medicine, University of Minnesota, Minnesota 55455 (United States)

2014-02-15T23:59:59.000Z

377

Monitoring CO 2 sequestration into deep saline aquifer and associated salt intrusion using coupled multiphase flow modeling and time lapse electrical resistivity tomography  

SciTech Connect (OSTI)

Successful geological storage and sequestration of carbon dioxide (CO2) require efficient monitoring of the migration of CO2 plume during and after large-scale injection in order to verify the containment of the injected CO2 within the target formation and to evaluate potential leakage risk. Field studies have shown that surface and cross-borehole electrical resistivity tomography (ERT) can be a useful tool in imaging and characterizing solute transport in heterogeneous subsurface. In this synthetic study, we have coupled a 3-D multiphase flow model with a parallel 3-D time-lapse ERT inversion code to explore the feasibility of using time-lapse ERT for simultaneously monitoring the migration of CO2 plume in deep saline formation and potential brine intrusion into shallow fresh water aquifer. Direct comparisons of the inverted CO2 plumes resulting from ERT with multiphase flow simulation results indicate the ERT could be used to delineate the migration of CO2 plume. Detailed comparisons on the locations, sizes and shapes of CO2 plume and intruded brine plumes suggest that ERT inversion tends to underestimate the area review of the CO2 plume, but overestimate the thickness and total volume of the CO2 plume. The total volume of intruded brine plumes is overestimated as well. However, all discrepancies remain within reasonable ranges. Our study suggests that time-lapse ERT is a useful monitoring tool in characterizing the movement of injected CO2 into deep saline aquifer and detecting potential brine intrusion under large-scale field injection conditions.

Chuan Lu; CHI Zhang; Hai Hanag; Timothy C. Johnson

2014-04-01T23:59:59.000Z

378

The Effect of a Contrast Agent on Proton Beam Range in Radiotherapy Planning Using Computed Tomography for Patients With Locoregionally Advanced Lung Cancer  

SciTech Connect (OSTI)

Purpose: We evaluated the effect of a contrast agent (CA) on proton beam range in a treatment planning system (TPS) for patients with locoregionally advanced lung cancer. Methods and Materials: Two sets of computed tomography (CT) images (with and without CA) were obtained from 20 patients with lung cancer. Because the increase in Hounsfield unit ( Increment HU) value of the heart and great vessels due to the effect of CA is most prominent among thoracic structures, to evaluate the effect of CA on proton beam range in the TPS, we compared the calculated distal ranges in the plan with CA-enhanced CT with those with corrected CT, in which the HU values of the heart and great vessels in the CA-enhanced CT were replaced by average HU values obtained from the unenhanced CT. Results: The mean Increment HU value and the longest length of the heart and great vessels within the proton beam path in the field that passed through these structures were 189 {+-} 29 HU (range, 110-250 HU) and 7.1 {+-} 1.1 cm (range, 2.6-11.2 cm), respectively. The mean distal range error in the TPS because of the presence of CA was 1.0 {+-} 0.7 cm (range, 0.2-2.6 cm). Conclusion: If CA-enhanced CT images are used for radiotherapy planning using a proton beam for the treatment of lung cancer, our results suggest that the HU values of the heart and great vessels should be replaced by the average HU values of soft tissue to avoid discrepancies between planned and delivered doses.

Hwang, Ui-Jung; Shin, Dong Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Kim, Tae Hyun, E-mail: k2onco@naver.com [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Moon, Sung Ho; Lim, Young Kyung; Jeong, Hojin; Rah, Jeong-Eun; Kim, Sang Soo; Kim, Joo-Young; Kim, Dae Yong; Park, Sung Yong; Cho, Kwan Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of)

2011-11-15T23:59:59.000Z

379

Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control  

SciTech Connect (OSTI)

The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.

Cheng, D.C.; Chung, F.; Burns, R.J.; Houston, P.L.; Feindel, C.M. (Toronto Hospital, Ontario (Canada))

1989-12-01T23:59:59.000Z

380

Assessing Respiration-Induced Tumor Motion and Internal Target Volume Using Four-Dimensional Computed Tomography for Radiotherapy of Lung Cancer  

SciTech Connect (OSTI)

Purpose: To assess three-dimensional tumor motion caused by respiration and internal target volume (ITV) for radiotherapy of lung cancer. Methods and Materials: Respiration-induced tumor motion was analyzed for 166 tumors from 152 lung cancer patients, 57.2% of whom had Stage III or IV non-small-cell lung cancer. All patients underwent four-dimensional computed tomography (4DCT) during normal breathing before treatment. The expiratory phase of 4DCT images was used as the reference set to delineate gross tumor volume (GTV). Gross tumor volumes on other respiratory phases and resulting ITVs were determined using rigid-body registration of 4DCT images. The association of GTV motion with various clinical and anatomic factors was analyzed statistically. Results: The proportions of tumors that moved >0.5 cm along the superior-inferior (SI), lateral, and anterior-posterior (AP) axes during normal breathing were 39.2%, 1.8%, and 5.4%, respectively. For 95% of the tumors, the magnitude of motion was less than 1.34 cm, 0.40 cm, and 0.59 cm along the SI, lateral, and AP directions. The principal component of tumor motion was in the SI direction, with only 10.8% of tumors moving >1.0 cm. The tumor motion was found to be associated with diaphragm motion, the SI tumor location in the lung, size of the GTV, and disease T stage. Conclusions: Lung tumor motion is primarily driven by diaphragm motion. The motion of locally advanced lung tumors is unlikely to exceed 1.0 cm during quiet normal breathing except for small lesions located in the lower half of the lung.

Liu, H. Helen [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: hliu@mdanderson.org; Balter, Peter [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Tutt, Teresa [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Choi, Bum [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Zhang, Joy [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Wang, Catherine [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Chi, Melinda [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Luo Dershan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Pan Tinsu [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Hunjan, Sandeep [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Starkschall, George [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Rosen, Isaac [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Prado, Karl [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Liao Zhongxing; Chang, Joe; Komaki, Ritsuko; Cox, James D. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe; Dong Lei [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2007-06-01T23:59:59.000Z

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381

Assessment of Gross Tumor Volume Regression and Motion Changes During Radiotherapy for Non-Small-Cell Lung Cancer as Measured by Four-Dimensional Computed Tomography  

SciTech Connect (OSTI)

Purpose: To investigate the magnitudes of the changes in mobility and volume of locally advanced non-small-cell lung cancer (NSCLC) tumors during radiotherapy, using four-dimensional computed tomography (4DCT). Methods and Materials: Five to ten 4DCT data sets were acquired weekly for each of 8 patients throughout treatment. Gross tumor volumes (GTVs) were outlined on each data set. Volumes and coordinates of the GTV centroids were calculated at the 0 (end-inspiration) and 50% (end-expiration) respiration phases. Trends in magnitudes of intrafraction and interfraction positional variations were assessed for the GTV and internal target volume (ITV) during treatment. Results: Tumor volume reduction ranged from 20% to 71% (end-inspiration) and from 15% to 70% (end-expiration). Increased tumor mobility was observed in the superior-inferior and anterior-posterior directions. However, no trends in tumor motion were observed. Motion along the superior-inferior direction was significantly greater (p < 0.001), with mean {+-} SD values of 0.86 {+-} 0.19 cm, as compared with 0.39 {+-} 0.08 cm and 0.19 {+-} 0.05 cm in the anterior-posterior and right-left directions, respectively. A marginally significant (p = 0.049) increase in total GTV positional variation was observed with increasing treatment weeks, and similar results were seen for the interfractional ITV mobility. Conclusions: Because of changes in tumor size and mobility, an explicit initial determination of the ITV may not be sufficient, especially where small setup margins are used. Repeat 4DCT scans might be warranted for highly mobile tumors to reduce the potential for missing the tumor.

Britton, Keith R. [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States)]. E-mail: kbritton@mdanderson.org; Starkschall, George [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Tucker, Susan L. [Department of Biostatistics and Applied Mathematics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Pan Tinsu [Department of Imaging Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Nelson, Christopher [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Chang, Joe Y. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Cox, James D. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Mohan, Radhe [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Komaki, Ritsuko [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston TX (United States)

2007-07-15T23:59:59.000Z

382

Clinical Evaluation of Spatial Accuracy of a Fusion Imaging Technique Combining Previously Acquired Computed Tomography and Real-Time Ultrasound for Imaging of Liver Metastases  

SciTech Connect (OSTI)

Purpose: This study was designed to evaluate the spatial accuracy of matching volumetric computed tomography (CT) data of hepatic metastases with real-time ultrasound (US) using a fusion imaging system (VNav) according to different clinical settings. Methods: Twenty-four patients with one hepatic tumor identified on enhanced CT and US were prospectively enrolled. A set of three landmarks markers was chosen on CT and US for image registration. US and CT images were then superimposed using the fusion imaging display mode. The difference in spatial location between the tumor visible on the CT and the US on the overlay images (reviewer no. 1, comment no. 2) was measured in the lateral, anterior-posterior, and vertical axis. The maximum difference (Dmax) was evaluated for different predictive factors.CT performed 1-30 days before registration versus immediately before. Use of general anesthesia for CT and US versus no anesthesia.Anatomic landmarks versus landmarks that include at least one nonanatomic structure, such as a cyst or a calcificationResultsOverall, Dmax was 11.53 {+-} 8.38 mm. Dmax was 6.55 {+-} 7.31 mm with CT performed immediately before VNav versus 17.4 {+-} 5.18 with CT performed 1-30 days before (p < 0.0001). Dmax was 7.05 {+-} 6.95 under general anesthesia and 16.81 {+-} 6.77 without anesthesia (p < 0.0015). Landmarks including at least one nonanatomic structure increase Dmax of 5.2 mm (p < 0.0001). The lowest Dmax (1.9 {+-} 1.4 mm) was obtained when CT and VNav were performed under general anesthesia, one immediately after the other. Conclusions: VNav is accurate when adequate clinical setup is carefully selected. Only under these conditions (reviewer no. 2), liver tumors not identified on US can be accurately targeted for biopsy or radiofrequency ablation using fusion imaging.

Hakime, Antoine, E-mail: thakime@yahoo.com; Deschamps, Frederic; Garcia Marques de Carvalho, Enio; Teriitehau, Christophe; Auperin, Anne; De Baere, Thierry [Gustave Roussy Institute (France)

2011-04-15T23:59:59.000Z

383

Zeeman tomography of magnetic white dwarfs IV. The complex field structure of the polars EF Eri, BL Hyi, and CP Tuc  

E-Print Network [OSTI]

The magnetic fields of the accreting white dwarfs (WDs) in magnetic cataclysmic variables (mCVs) determine the accretion geometries, the emission properties, and the secular evolution of these objects. We determine the structure of the surface magnetic fields of the WDs primaries in magnetic CVs using Zeeman tomography. Our study is based on orbital-phase resolved optical flux and circular polarization spectra of the polars EF Eri, BL Hyi, and CP Tuc obtained with FORS1 at the ESO VLT. An evolutionary algorithm is used to synthesize best fits to these spectra from an extensive database of pre-computed Zeeman spectra. The general approach has been described in previous papers of this series. The results achieved with simple geometries as centered or offset dipoles are not satisfactory. Significantly improved fits are obtained for multipole expansions that are truncated at degree l(max)=3 or 5 and include all tesseral and sectoral components with 0<=m<=l. The most frequent field strengths of 13, 18, and 10MG for EF Eri, BL Hyi, CP Tuc and the ranges of field strength covered are similar for the dipole and multipole models, but only the latter provide access to accreting matter at the right locations on the WD. The results suggest that the field geometries of the WDs in short-period mCVs are quite complex with strong contributions from multipoles higher than the dipole in spite of a typical age of the WDs in CVs in excess of 1 Gyr. It is feasible to derive the surface field structure of an accreting WD from phase-resolved low-state circular spectropolarimetry of sufficiently high signal-to-noise ratio. The fact that independent information is available on the strength and direction of the field in the accretion spot from high-state observations helps in unraveling the global field structure.

K. Beuermann; F. Euchner; K. Reinsch; S. Jordan; B. T. Gaensicke

2006-10-26T23:59:59.000Z

384

Contribution of atom-probe tomography to a better understanding of glass alteration mechanisms: application to a nuclear glass specimen altered 25 years in a granitic environment  

SciTech Connect (OSTI)

We report and discuss results of atom probe tomography (APT) and energy-filtered transmission electron microscopy (EFTEM) applied to a borosilicate glass sample of nuclear interest altered for nearly 26 years at 90°C in a confined granitic medium in order to better understand the rate-limiting mechanisms under conditions representative of a deep geological repository for vitrified radioactive waste. The APT technique allows the 3D reconstruction of the elemental distribution at the reactive interphase with sub-nanometer precision. Profiles of the B distribution at pristine glass/hydrated glass interface obtained by different techniques are compared to show the challenge of accurate measurements of diffusion profiles at this buried interface on the nanometer length scale. Our results show that 1) Alkali from the glass and hydrogen from the solution exhibit anti-correlated 15 ± 3 nm wide gradients located between the pristine glass and the hydrated glass layer, 2) boron exhibits an unexpectedly sharp profile located just at the outside of the alkali/H interdiffusion layer; this sharp profile is more consistent with a dissolution front than a diffusion-controlled release of boron. The resulting apparent diffusion coefficients derived from the Li and H profiles are DLi = 1.5 × 10-22 m2.s-1 and DH = 6.8 × 10-23 m2.s-1. These values are around two orders of magnitude lower than those observed at the very beginning of the alteration process, which suggests that interdiffusion is slowed at high reaction progress by local conditions that could be related to the porous structure of the interphase. As a result, the accessibility of water to the pristine glass could be the rate-limiting step in these conditions. More generally, these findings strongly support the importance of interdiffusion coupled with hydrolysis reactions of the silicate network on the long-term dissolution rate, contrary to what has been suggested by recent interfacial dissolution-precipitation models for silicate minerals.

Gin, Stephane [CEA Marcoule DTCD SECM LCLT, Bagnols-sur-Ceze (France); Ryan, Joseph V. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Schreiber, Daniel K. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Neeway, James J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Cabie, M. [Aix-Marseille Universite, CP2M, Marseille (France)

2013-06-26T23:59:59.000Z

385

AN INTENSE LOW ENERGY MUON SOURCE FOR THE MUON COLLIDER  

E-Print Network [OSTI]

AN INTENSE LOW ENERGY MUON SOURCE FOR THE MUON COLLIDER D. Taqqu Paul Scherrer Institut, Villigen, CH Abstract A scheme for obtaining an intense source of low energy muons is described. It is based of the decay muons an intense intermediate energy muon beam is obtained. For the specific case of negative

McDonald, Kirk

386

Note: Design and construction of a multi-scale, high-resolution, tube-generated X-Ray computed-tomography system for three-dimensional (3D) imaging  

SciTech Connect (OSTI)

The design and construction of a high resolution modular x-ray computed tomography (XCT) system is described. The approach for meeting a specified set of performance goals tailored toward experimental versatility is highlighted. The instrument is unique in its detector and x-ray source configuration, both of which enable elevated optimization of spatial and temporal resolution. The process for component selection is provided. The selected components are specified, the custom component design discussed, and the integration of both into a fully functional XCT instrument is outlined. The novelty of this design is a new lab-scale detector and imaging optimization through x-ray source and detector modularity.

Mertens, J. C. E.; Williams, J. J.; Chawla, Nikhilesh [Materials Science and Engineering, Security and Defense Systems Initiative, Arizona State University, 781 E. Terrace Road, ISTB4, Tempe, Arizona 85287-5604 (United States)] [Materials Science and Engineering, Security and Defense Systems Initiative, Arizona State University, 781 E. Terrace Road, ISTB4, Tempe, Arizona 85287-5604 (United States)

2014-01-15T23:59:59.000Z

387

Rare muon processes  

SciTech Connect (OSTI)

The status of rare muon processes as tests of the standard model is reviewed with the emphasis on results that are expected from experiments in the near future.

Cooper, M.D.

1993-01-01T23:59:59.000Z

388

Rare muon processes  

SciTech Connect (OSTI)

The status of rare muon processes as tests of the standard model is reviewed with the emphasis on results that are expected from experiments in the near future.

Cooper, M.D.; The MEGA Collaboration

1993-05-01T23:59:59.000Z

389

A Comparison of Amplitude-Based and Phase-Based Positron Emission Tomography Gating Algorithms for Segmentation of Internal Target Volumes of Tumors Subject to Respiratory Motion  

SciTech Connect (OSTI)

Purpose: To quantitatively compare the accuracy of tumor volume segmentation in amplitude-based and phase-based respiratory gating algorithms in respiratory-correlated positron emission tomography (PET). Methods and Materials: List-mode fluorodeoxyglucose-PET data was acquired for 10 patients with a total of 12 fluorodeoxyglucose-avid tumors and 9 lymph nodes. Additionally, a phantom experiment was performed in which 4 plastic butyrate spheres with inner diameters ranging from 1 to 4 cm were imaged as they underwent 1-dimensional motion based on 2 measured patient breathing trajectories. PET list-mode data were gated into 8 bins using 2 amplitude-based (equal amplitude bins [A1] and equal counts per bin [A2]) and 2 temporal phase-based gating algorithms. Gated images were segmented using a commercially available gradient-based technique and a fixed 40% threshold of maximum uptake. Internal target volumes (ITVs) were generated by taking the union of all 8 contours per gated image. Segmented phantom ITVs were compared with their respective ground-truth ITVs, defined as the volume subtended by the tumor model positions covering 99% of breathing amplitude. Superior-inferior distances between sphere centroids in the end-inhale and end-exhale phases were also calculated. Results: Tumor ITVs from amplitude-based methods were significantly larger than those from temporal-based techniques (P=.002). For lymph nodes, A2 resulted in ITVs that were significantly larger than either of the temporal-based techniques (P<.0323). A1 produced the largest and most accurate ITVs for spheres with diameters of ?2 cm (P=.002). No significant difference was shown between algorithms in the 1-cm sphere data set. For phantom spheres, amplitude-based methods recovered an average of 9.5% more motion displacement than temporal-based methods under regular breathing conditions and an average of 45.7% more in the presence of baseline drift (P<.001). Conclusions: Target volumes in images generated from amplitude-based gating are larger and more accurate, at levels that are potentially clinically significant, compared with those from temporal phase-based gating.

Jani, Shyam S., E-mail: sjani@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); Robinson, Clifford G. [Department of Radiation Oncology, Siteman Cancer Center, Washington University in St Louis, St Louis, Missouri (United States); Dahlbom, Magnus [Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); White, Benjamin M.; Thomas, David H.; Gaudio, Sergio; Low, Daniel A.; Lamb, James M. [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States)

2013-11-01T23:59:59.000Z

390

Assessment of Interfraction Patient Setup for Head-and-Neck Cancer Intensity Modulated Radiation Therapy Using Multiple Computed Tomography-Based Image Guidance  

SciTech Connect (OSTI)

Purpose: Various image guidance systems are commonly used in conjunction with intensity modulated radiation therapy (IMRT) in head-and-neck cancer irradiation. The purpose of this study was to assess interfraction patient setup variations for 3 computed tomography (CT)-based on-board image guided radiation therapy (IGRT) modalities. Methods and Materials: A total of 3302 CT scans for 117 patients, including 53 patients receiving megavoltage cone-beam CT (MVCBCT), 29 receiving kilovoltage cone-beam CT (KVCBCT), and 35 receiving megavoltage fan-beam CT (MVFBCT), were retrospectively analyzed. The daily variations in the mediolateral (ML), craniocaudal (CC), and anteroposterior (AP) dimensions were measured. The clinical target volume-to-planned target volume (CTV-to-PTV) margins were calculated using 2.5? + 0.7 ?, where ? and ? were systematic and random positioning errors, respectively. Various patient characteristics for the MVCBCT group, including weight, weight loss, tumor location, and initial body mass index, were analyzed to determine their possible correlation with daily patient setup. Results: The average interfraction displacements (± standard deviation) in the ML, CC, and AP directions were 0.5 ± 1.5, ?0.3 ± 2.0, and 0.3 ± 1.7 mm (KVCBCT); 0.2 ± 1.9, ?0.2 ± 2.4, and 0.0 ± 1.7 mm (MVFBCT); and 0.0 ± 1.8, 0.5 ± 1.7, and 0.8 ± 3.0 mm (MVCBCT). The day-to-day random errors for KVCBCT, MVFBCT, and MVCBCT were 1.4-1.6, 1.7, and 2.0-2.1 mm. The interobserver variations were 0.8, 1.1, and 0.7 mm (MVCBCT); 0.5, 0.4, and 0.8 mm (MVFBCT); and 0.5, 0.4, and 0.6 mm (KVCBCT) in the ML, CC, and AP directions, respectively. The maximal calculated uniform CTV-to-PTV margins were 5.6, 6.9, and 8.9 mm for KVCBCT, MVFBCT, and MVCBCT, respectively. For the evaluated patient characteristics, the calculated margins for different patient parameters appeared to differ; analysis of variance (ANOVA) and/or t test analysis found no statistically significant setup difference in any direction. Conclusions: Daily random setup errors and CTV-to-PTV margins for treatment of head-and-neck cancer were affected by imaging quality. Our data indicated that larger margins were associated with MVFBCT and MVCBCT, compared with smaller margins for KVCBCT. IGRT modalities with better image quality are encouraged in clinical practice.

Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, David of Geffen School of Medicine at UCLA, Los Angeles, California (United States); Hu, Angie Y. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States); Lee, Steve P.; Lee, Percy; DeMarco, John [Department of Radiation Oncology, David of Geffen School of Medicine at UCLA, Los Angeles, California (United States)] [Department of Radiation Oncology, David of Geffen School of Medicine at UCLA, Los Angeles, California (United States); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)] [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Steinberg, Michael L.; Kupelian, Patrick; Low, Daniel [Department of Radiation Oncology, David of Geffen School of Medicine at UCLA, Los Angeles, California (United States)] [Department of Radiation Oncology, David of Geffen School of Medicine at UCLA, Los Angeles, California (United States)

2013-07-01T23:59:59.000Z

391

Development and Implementation of 3-D, High Speed Capacitance Tomography for Imaging Large-Scale, Cold-Flow Circulating Fluidized Bed  

SciTech Connect (OSTI)

A detailed understanding of multiphase flow behavior inside a Circulating Fluidized Bed (CFB) requires a 3-D technique capable of visualizing the flow field in real-time. Electrical Capacitance Volume Tomography (ECVT) is a newly developed technique that can provide such measurements. The attractiveness of the technique is in its low profile sensors, fast imaging speed and scalability to different section sizes, low operating cost, and safety. Moreover, the flexibility of ECVT sensors enable them to be designed around virtually any geometry, rendering them suitable to be used for measurement of solid flows in exit regions of the CFB. Tech4Imaging LLC has worked under contract with the U.S. Department of Energyâ??s National Energy Technology Laboratory (DOE NETL) to develop an ECVT system for cold flow visualization and install it on a 12 inch ID circulating fluidized bed. The objective of this project was to help advance multi-phase flow science through implementation of an ECVT system on a cold flow model at DOE NETL. This project has responded to multi-phase community and industry needs of developing a tool that can be used to develop flow models, validate computational fluid dynamics simulations, provide detailed real-time feedback of process variables, and provide a comprehensive understating of multi-phase flow behavior. In this project, a complete ECVT system was successfully developed after considering different potential electronics and sensor designs. The system was tested at various flow conditions and with different materials, yielding real-time images of flow interaction in a gas-solid flow system. The system was installed on a 12 inch ID CFB of the US Department of Energy, Morgantown Labs. Technical and economic assessment of Scale-up and Commercialization of ECVT was also conducted. Experiments conducted with larger sensors in conditions similar to industrial settings are very promising. ECVT has also the potential to be developed for imaging multi-phase flow systems in high temperature and high pressure conditions, typical in many industrial applications.

Qussai Marashdeh

2012-09-30T23:59:59.000Z

392

Muons and Neutrinos 2007  

E-Print Network [OSTI]

This paper is the written version of the rapporteur talk on Section HE-2, muons and neutrinos, presented at the 30th International Cosmic Ray Conference, Merida, Yucatan, July 11, 2007. Topics include atmospheric muons and neutrinos, solar neutrinos and astrophysical neutrinos as well as calculations and instrumentation related to these topics.

Thomas K. Gaisser

2008-01-29T23:59:59.000Z

393

Fourier analysis and synthesis tomography.  

SciTech Connect (OSTI)

Most far-field optical imaging systems rely on a lens and spatially-resolved detection to probe distinct locations on the object. We describe and demonstrate a novel high-speed wide-field approach to imaging that instead measures the complex spatial Fourier transform of the object by detecting its spatially-integrated response to dynamic acousto-optically synthesized structured illumination. Tomographic filtered backprojection is applied to reconstruct the object in two or three dimensions. This technique decouples depth-of-field and working-distance from resolution, in contrast to conventional imaging, and can be used to image biological and synthetic structures in fluoresced or scattered light employing coherent or broadband illumination. We discuss the electronically programmable transfer function of the optical system and its implications for imaging dynamic processes. Finally, we present for the first time two-dimensional high-resolution image reconstructions demonstrating a three-orders-of-magnitude improvement in depth-of-field over conventional lens-based microscopy.

Wagner, Kelvin H. (University of Colorado at Boulder, Boulder, CO); Sinclair, Michael B.; Feldkuhn, Daniel (University of Colorado at Boulder, Boulder, CO)

2010-05-01T23:59:59.000Z

394

Mathematical Problems of Thermoacoustic Tomography  

E-Print Network [OSTI]

(y,s) = ?integraldisplay 0 ?R(s,?) ?integraldisplay 0 g(y,r)I(r,?)drd?. The key ingredient in the proof of Theorem A.1 is the following identity, which is equivalent to a range description of operator T (see Remark D.3): Theorem A.4 Suppose that ? is a ball, f ? C?0... . . . . . . . . . . . . . . . . . . . 6 C. Publications and presentations of the results . . . . . . . . 7 II INVERSION FORMULAS . . . . . . . . . . . . . . . . . . . . . 9 A. Introduction to the problem and main results . . . . . . . 9 B. Derivation of Theorem A.1 from Theorem A.4...

Nguyen, Linh V.

2010-10-12T23:59:59.000Z

395

Ultrasound-modulated optical tomography  

E-Print Network [OSTI]

a0a2a1a4a3a6a5a2a7a2a8a10a9a11a0a13a12a13a14a16a15a18a17a19a9a11a14a20a0a13a1a21a7a22a3a24a23a25a14 a9a11a26a27a3a6a28a30a29a24a7a13a1a31a3a6a9a11a17a19a9a11a32a11a5a2a7a2a26a27a33a27a34 a7a35a14a37a36a39a38a40a38a18a41a43a42a45a44a47a46a48a44a47a36... a39a49a51a50 a52a54a53 a33a13a7a13a23a56a55a57a9a11a12a58a12a2a7a13a17 a8a10a59 a52a10a60 a36a61a44a62a44a47a41a43a63a64a44a47a49a20a44a54a65a10a41a66a9a11a67a69a68a43a41a11a49a51a70a71a32a66a42a62a46a51a63a10a59a10a46a72a44a54a41a66a8a73a44a54a59a10...

Nam, Haewon

2004-09-30T23:59:59.000Z

396

Muon Collider Progress: Accelerators  

E-Print Network [OSTI]

A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 \\times 10^34 cm^-2s^-1. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance ("cooling"). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

Michael S. Zisman

2011-09-14T23:59:59.000Z

397

The LHCb Muon System  

E-Print Network [OSTI]

The ability to provide fast muon triggering and efficient offline muon identification is an essential feature of the LHCb experiment. The muon detector is required to have a high efficiency over a large area and an appropriate time resolution to identify the bunch crossing for level–0 triggers. The LHCb muon detector consists of five stations equipped with 1368 Multi Wire Proportional Chambers and 12 Gas Electron Multiplier chambers. The technical design of the chambers is briefly presented and the Quality Control procedures during the various construction steps are described. The method developed for gas gain uniformity measurement is also described together with the results on efficiency of detectors fully equipped with the front–end electronics, obtained from tests with cosmic rays.

Lenzi, Michela

2005-01-01T23:59:59.000Z

398

TETRA MUON COOLING RING  

SciTech Connect (OSTI)

We give a brief overview of recent simulation activities on the design of neutrino factories. Simulation work is ongoing on many aspects of a potential facility, including proton drivers, pion collection and decay channels, phase rotation, ionization cooling, and muon accelerators.

KAHN,S.A.FERNOW,R.C.BALBEKOV,V.RAJA,R.USUBOV,Z.

2003-11-18T23:59:59.000Z

399

Muon capture in hydrogen  

E-Print Network [OSTI]

Theoretical difficulties in reconciling the measured rates for ordinary and radiative muon capture are discussed, based on heavy-baryon chiral perturbation theory. We also examine ambiguity in our analysis due to the formation of p$\\mu$p molecules in the liquid hydrogen target.

S. Ando; F. Myhrer; K. Kubodera

2001-10-30T23:59:59.000Z

400

Muon capture at PSI  

E-Print Network [OSTI]

Measuring the rate of muon capture in hydrogen provides one of the most direct ways to study the axial current of the nucleon. The MuCap experiment uses a negative muon beam stopped in a time projection chamber operated with ultra-pure hydrogen gas. Surrounded by a decay electron detector, the lifetime of muons in hydrogen can be measured to determine the singlet capture rate Lambda_s to a final precision of 1%. The capture rate determines the nucleon's pseudoscalar form factor g_p. A first result, g_p = 7.3 +- 1.1, has been published and the final analysis of the full statistics will reduce the error by a factor of up to 3. Muon capture on the deuteron probes the weak axial current in the two-nucleon system. Within the framework of effective field theories the calculation of such two-nucleon processes involving the axial current requires the knowledge of one additional low energy constant which can be extracted from the doublet capture rate Lambda_d. The same constant then allows to model-independently calculate related processes such as solar pp-fusion or neutrino-deuteron scattering. The MuSun experiment will deduce Lambda_d to better than 1.5%. The experiment uses the MuCap detection setup with a new time projection chamber operated with deuterium at 30K and several hardware upgrades. The system is currently fully commissioned and the main physics data taking will start in 2011.

Peter Winter

2010-12-17T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Superconducting solenoids for the Muon collider  

E-Print Network [OSTI]

muon collider has superconducting solenoids as an integralLBNL-44303 SCMAG-690 Superconducting Solenoids for the MuonDE-AC03-76SFOOO98. J Superconducting Solenoids for the Muon

Green, M.A.

2011-01-01T23:59:59.000Z

402

SU-E-I-02: A Framework to Perform Batch Simulations of Computational Voxel Phantoms to Study Organ Doses in Computed Tomography Using a Commercial Monte Carlo Software Package  

SciTech Connect (OSTI)

Purpose: ImpactMC (CT Imaging, Erlangen, Germany) is a Monte Carlo (MC) software package that offers a GPU enabled, user definable and validated method for 3D dose distribution calculations for radiography and Computed Tomography (CT). ImpactMC, in and of itself, offers limited capabilities to perform batch simulations. The aim of this work was to develop a framework for the batch simulation of absorbed organ dose distributions from CT scans of computational voxel phantoms. Methods: The ICRP 110 adult Reference Male and Reference Female computational voxel phantoms were formatted into compatible input volumes for MC simulations. A Matlab (The MathWorks Inc., Natick, MA) script was written to loop through a user defined set of simulation parameters and 1) generate input files required for the simulation, 2) start the MC simulation, 3) segment the absorbed dose for organs in the simulated dose volume and 4) transfer the organ doses to a database. A demonstration of the framework is made where the glandular breast dose to the adult Reference Female phantom, for a typical Chest CT examination, is investigated. Results: A batch of 48 contiguous simulations was performed with variations in the total collimation and spiral pitch. The demonstration of the framework showed that the glandular dose to the right and left breast will vary depending on the start angle of rotation, total collimation and spiral pitch. Conclusion: The developed framework provides a robust and efficient approach to performing a large number of user defined MC simulations with computational voxel phantoms in CT (minimal user interaction). The resulting organ doses from each simulation can be accessed through a database which greatly increases the ease of analyzing the resulting organ doses. The framework developed in this work provides a valuable resource when investigating different dose optimization strategies in CT.

Bujila, R; Nowik, P; Poludniowski, G [Karolinska University Hospital, Stockholm, Stockholm (Sweden)

2014-06-01T23:59:59.000Z

403

Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with {sup 68}Ga-DOTA-octreotide: A potential PET tracer for beta cell mass measurement  

SciTech Connect (OSTI)

Highlights: •PET images showed high uptake of {sup 68}Ga-DOTA-octreotide in the normal pancreas. •{sup 68}Ga-DOTA-octreotide specifically binds to somatostatin receptors in the pancreas. •The pancreatic uptake of {sup 68}Ga-DOTA-octreotide was decreased in the diabetic rats. •{sup 68}Ga-DOTA-octreotide could be a candidate PET probe to measure the beta cell mass. -- Abstract: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with {sup 68}Gallium ({sup 68}Ga). After intravenous injection of {sup 68}Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that {sup 68}Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of {sup 68}Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with {sup 68}Ga-DOTA-octreotide could be a potential tool for evaluating BCM.

Sako, Takeo [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan) [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)] [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Senda, Michio [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan) [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Watanabe, Yasuyoshi, E-mail: yywata@riken.jp [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)] [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)

2013-12-06T23:59:59.000Z

404

Stochastic cooling in muon colliders  

SciTech Connect (OSTI)

Analysis of muon production techniques for high energy colliders indicates the need for rapid and effective beam cooling in order that one achieve luminosities > 10{sup 30} cm{sup {minus}2}s{sup {minus}1} as required for high energy physics experiments. This paper considers stochastic cooling to increase the phase space density of the muons in the collider. Even at muon energies greater than 100 GeV, the number of muons per bunch must be limited to {approximately}10{sup 3} for the cooling rate to be less than the muon lifetime. With such a small number of muons per bunch, the final beam emittance implied by the luminosity requirement is well below the thermodynamic limit for beam electronics at practical temperatures. Rapid bunch stacking after the cooling process can raise the number of muons per bunch to a level consistent with both the luminosity goals and with practical temperatures for the stochastic cooling electronics. A major advantage of our stochastic cooling/stacking scheme over scenarios that employ only ionization cooling is that the power on the production target can be reduced below 1 MW.

Barletta, W.A.; Sessler, A.M.

1993-09-01T23:59:59.000Z

405

Muon Collider Task Force Report  

SciTech Connect (OSTI)

Muon Colliders offer a possible long term path to lepton-lepton collisions at center-of-mass energies {radical}s {ge} 1 TeV. In October 2006 the Muon Collider Task Force (MCTF) proposed a program of advanced accelerator R&D aimed at developing the Muon Collider concept. The proposed R&D program was motivated by progress on Muon Collider design in general, and in particular, by new ideas that have emerged on muon cooling channel design. The scope of the proposed MCTF R&D program includes muon collider design studies, helical cooling channel design and simulation, high temperature superconducting solenoid studies, an experimental program using beams to test cooling channel RF cavities and a 6D cooling demonstration channel. The first year of MCTF activities are summarized in this report together with a brief description of the anticipated FY08 R&D activities. In its first year the MCTF has made progress on (1) Muon Collider ring studies, (2) 6D cooling channel design and simulation studies with an emphasis on the HCC scheme, (3) beam preparations for the first HPRF cavity beam test, (4) preparations for an HCC four-coil test, (5) further development of the MANX experiment ideas and studies of the muon beam possibilities at Fermilab, (6) studies of how to integrate RF into an HCC in preparation for a component development program, and (7) HTS conductor and magnet studies to prepare for an evaluation of the prospects for of an HTS high-field solenoid build for a muon cooling channel.

Ankenbrandt, C.; Alexahin, Y.; Balbekov, V.; Barzi, E.; Bhat, C.; Broemmelsiek, D.; Bross, A.; Burov, A.; Drozhdin, A.; Finley, D.; Geer, S.; /Fermilab /Argonne /Brookhaven /Jefferson Lab /LBL, Berkeley /MUONS Inc., Batavia /UCLA /UC, Riverside /Mississippi U.

2007-12-01T23:59:59.000Z

406

Muon catalyzed fusion  

SciTech Connect (OSTI)

This paper presents an overview of the program and results of our experiment performed by a European-American collatoration at the Swiss Institute of Nuclear Research. Systematic investigations of the low temperature region (23K to 300K) reveal a surprisingly rich physics of mesoatomic and mesomolecular processes, unparalleled in other systems of isotopic hydrogen mixtures. A dramatic density dependence of the reaction rates is found. The rich structure in the time spectra of the fusion neutrons observed at low gas density yields first evidence for new effects, most likely strong contributions from reactions of hot muonic atoms. The important question of muon losses due to He sticking is investigated by different methods and over a wide range of tritium concentrations.

Breunlich, W.H.; Cargnelli, M.; Marton, J.; Naegele, N.; Pawlek, P.; Scrinzi, A.; Werner, J.; Zmeskal, J.; Bistirlich, J.; Crowe, K.M.

1986-01-01T23:59:59.000Z

407

The US muon accelerator program  

E-Print Network [OSTI]

A directed R&D program is presently underway in the U.S. to evaluate the designs and technologies required to provide muon-based high energy physics (HEP) accelerator capabilities. Such capabilities have the potential to provide unique physics reach for the HEP community. An overview of the status of the designs for the neutrino factory and muon collider applications is provided. Recent progress in the technology R&D program is summarized.

Palmer, M A

2015-01-01T23:59:59.000Z

408

Muon Colliders: The Next Frontier  

ScienceCinema (OSTI)

Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

Yagmur Tourun

2010-01-08T23:59:59.000Z

409

Sediment isotope tomography (SIT) model version 1  

SciTech Connect (OSTI)

Geochronology using {sup 210}Pb is the principal method used to quantify sediment accumulation in rapidly depositing aquatic environments such as lakes, estuaries, continental shelves, and submarine canyons. This method is based on the radioactive decay of {sup 210}Pb with depth in a column of sediment. The decay through time of {sup 210}Pb P(t) is governed by the exponential law P(t) = P{sub 0} exp( -{lambda}t) where P{sub 0} is the surficial concentration at time t = 0, and {lambda} is the decay constant (3.114 {sm_bullet} 10{sup -2} year [yr]{sup -1} for {sup 210}Pb). If the sedimentation rate is constant, then elapsed time t is connected to burial depth x, through x = Vt where V is the sedimentation velocity. Accordingly, P(x) = P{sub 0}exp( -{lambda}x/V). The sedimentation velocity is obtained from an exponential fit to the measured {sup 210}Pb data P(x), with depth x.

Carroll, J.; Abraham, J.D.

1996-03-08T23:59:59.000Z

410

Study of scattering in positron emission tomography  

E-Print Network [OSTI]

an address for each coincident gamma-ray pair hence a line through the gamma-ray source. Line addresses collected at various angles are used to reconstruct an image of the radiating source. An experimental subset of the TAMU PET was used to investigate gamma-ray...

Aguiar, James

1998-01-01T23:59:59.000Z

411

Optimum phase space probabilities from quantum tomography  

SciTech Connect (OSTI)

We determine a positive normalised phase space probability distribution P with minimum mean square fractional deviation from the Wigner distribution W. The minimum deviation, an invariant under phase space rotations, is a quantitative measure of the quantumness of the state. The positive distribution closest to W will be useful in quantum mechanics and in time frequency analysis. The position-momentum correlations given by the distribution can be tested experimentally in quantum optics.

Roy, Arunabha S., E-mail: roy.arunabha@gmail.com [King's College, London (United Kingdom); Roy, S. M., E-mail: smroy@hbcse.tifr.res.in [HBCSE, Tata Institute of Fundamental Research, Mumbai (India)

2014-01-15T23:59:59.000Z

412

MICROLOCAL APPROACH TO TENSOR TOMOGRAPHY AND ...  

E-Print Network [OSTI]

Jan 10, 2007 ... ?f,vm? = fi1i2...im vi1 vi2 ...vim . ..... DN map for the wave equation (?2 ... This follows from the Jacobi theory of solving the eikonal equation.

2008-03-14T23:59:59.000Z

413

Imaging Tumour Hypoxia with Positron Emission Tomography  

E-Print Network [OSTI]

contrast may potentially impede visual detection of hypoxic regions, and has hampered diagnostic utility in routine practice. Therefore, considerable efforts have been made to develop hypoxia markers with improved pharmacokinetic properties (enhanced... ]Fluoroerythronitroimidazole PET. J Nucl Med 42(11): 1643–52. Lehtiö K, Oikonen V, Nyman S, Grönroos T, Roivainen A, Eskola O, Minn H (2003) Quantifying tumour hypoxia with fluorine–18–fluoroerythronitroimidazole ([18F]FETNIM) and PET using the tumour to plasma ratio. Eur J...

Fleming, Ian N.; Manavaki, Roido; Blower, Philip J.; West, Catharine; Williams, Kaye J.; Harris, Adrian L.; Domarkas, Juozas; Lord, Simon; Baldry, Claire; Gilbert, Fiona J.

2014-12-16T23:59:59.000Z

414

MULTIWAVE TOMOGRAPHY IN A CLOSED DOMAIN: AVERAGED ...  

E-Print Network [OSTI]

Time reversal in its classical form fails for this problem because the waves reflect ... The micrlocal analysis justifying the time reversal however would be much ...

2015-02-03T23:59:59.000Z

415

adnextumoren mittels positronen-emissions-tomographie: Topics...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

X3D im Browser ?bersicht 1. Einfache Programme in Form von Shaders 2. Einfache Zachmann, Gabriel 28 Sprachliche Mittel der nationalsozialistischen Propaganda. Open Access...

416

Longitudinal Dynamics and Tomography in the Tevatron  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Motivated by the desire to understand the longitudinal effects of beam-beam forces, we study the longitudinal dynamics of protons and anti-protons at injection and top energy in the Tevatron. Multi-turn data of the longitudinal profiles are captured to reveal information about frequencies of oscillation, and changes in the bunch distributions. Tomographic reconstruction is used to create phase space maps which are subsequently used to find the momentum distributions. Changes in these distributions for both proton and anti-proton beams are also followed through the operational cycle. We report on the details of interesting dynamics and some unexpected findings.

Stogin, J [Princeton U.; Sen, T [Fermilab; Moore, R S [Fermilab

2012-01-10T23:59:59.000Z

417

Azimuthal Jet Tomography at RHIC and LHC  

E-Print Network [OSTI]

A generic jet-energy loss model that is coupled to state-of-the-art hydrodynamic fields and interpolates between a wide class of running coupling pQCD-based and AdS/CFT-inspired models is compared to recent data on the azimuthal and transverse momentum dependence of high-pT pion nuclear modification factors and high-pT elliptic flow measured at RHIC and LHC. We find that RHIC data are surprisingly consistent with various scenarios considered. However, extrapolations to LHC energies favor running coupling pQCD-based models of jet-energy loss. While conformal holographic models are shown to be inconsistent with data, recent non-conformal generalizations of AdS holography may provide an alternative description.

Barbara Betz; Miklos Gyulassy

2014-02-14T23:59:59.000Z

418

Applying Compactness Constraints to Differential Traveltime Tomography  

E-Print Network [OSTI]

Tomographic imaging problems are typically ill-posed and often require the use of regularization techniques

Ajo-Franklin, Jonathan B.

2007-01-01T23:59:59.000Z

419

Temporal Integration of Seismic Traveltime Tomography  

E-Print Network [OSTI]

Time-lapse geophysical measurements and seismic imaging methods in particular are powerful techniques

Ajo-Franklin, Jonathan B.

2005-06-01T23:59:59.000Z

420

High energy neutron Computed Tomography developed  

E-Print Network [OSTI]

be observed behind high-density materials, such as depleted uranium or tungsten. Comparison of the high (bottom half) and foam (center teeth) phantom could be viewed through 76 mm of depleted uranium. Some ~ 3

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Functional photoacoustic tomography of animal brains  

E-Print Network [OSTI]

As described in previous literatures, 38,40 the photoacoustic signal ),( tp r at position r and time t is related to a heating source ),( tH r by the following wave equation: t tH C tp tc tp ps ? ? ?= ? ? ?? ),( ),( 1 ),( 2 2 2 2 r rr ? (1) where c...

Wang, Xueding

2005-11-01T23:59:59.000Z

422

APPLICATION Calcul de rais en tomographie sismique  

E-Print Network [OSTI]

modélisation 3D sont les sismo­ grammes collectés, lors de séismes, par différentes stations sismologiques

Genaud, Stéphane

423

APPLICATION Calcul de rais en tomographie sismique  

E-Print Network [OSTI]

modélisation 3D sont les sismo- grammes collectés, lors de séismes, par différentes stations sismologiques

Genaud, Stéphane

424

Reconstruction in tomography with diffracting sources  

E-Print Network [OSTI]

be expressed as pr(r,t) = - integraldisplay t+ T0 dt0 contintegraldisplay ? dSdp0(rd, ?0)partialdiffg1(r,t|rd ,t0)partialdiffn . (2.12) The physical meaning of (2.12) is that the time-reversed field before a certain time in R is equivalent to the field (caused...partialdiffg+/partialdiffn pr(r,t) approxequal -2 integraldisplay t+ T0 dt0 contintegraldisplay ? dSdp0(rd, ?0)partialdiffg+(r,t|rd ,t0)partialdiffn . (2.13) The physical meaning of (2.13) is that under certain conditions, time reversal can be approximated well...

Xu, Yuan

2005-02-17T23:59:59.000Z

425

System and method for ultrasonic tomography  

DOE Patents [OSTI]

A system and method for doing both transmission mode and reflection mode three-dimensional ultrasonic imagining. The multimode imaging capability may be used to provide enhanced detectability of cancer tumors within human breast, however, similar imaging systems are applicable to a number of other medical problems as well as a variety of non-medical problems in non-destructive evaluation (NDE).

Haddad, Waleed Sami (Dublin, CA)

2002-01-01T23:59:59.000Z

426

Addiction Studies with Positron Emission Tomography  

ScienceCinema (OSTI)

Brookhaven scientist Joanna Fowler describes Positron Emission Technology (PET) research at BNL which for the past 30 years has focused in the integration of basic research in radiotracer chemistry with the tools of neuroscience to develop new scientific

Joanna Fowler

2010-01-08T23:59:59.000Z

427

High energy neutron Computed Tomography developed  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2M HILLAdministrationHigh

428

BOUNDARY AND LENS RIGIDITY, TENSOR TOMOGRAPHY AND ...  

E-Print Network [OSTI]

Moscow, 50–73 (in Russian). 5. G. Besson, G. Courtois, and S. Gallot, Entropies et rigidités des espaces localement symétriques de courbure strictment négative

2007-09-25T23:59:59.000Z

429

X-ray Computed Tomography | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption byAbout SRNL Home SRNL main campusMore thanX-Ray ImagingfeedX-ray

430

High energy neutron Computed Tomography developed  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinement plasmas in thein the Assembly ofNa-ion batterye ne rgy

431

TE Connectivity Finds Answers in Tomography  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystallineForeign Object DamageSystemsU.S. TALKS BPA - Firm NTTE

432

Ground-based Microwave Cloud Tomography  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGetGraphene's 3DRise |EnergyVehiclesMeasurementMicrowave

433

Positron Emission Tomography (PET) and Positron Scanning  

Office of Scientific and Technical Information (OSTI)

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434

TE Connectivity Finds Answers in Tomography  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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435

Positron emission tomography and optical tissue imaging  

DOE Patents [OSTI]

A mobile compact imaging system that combines both PET imaging and optical imaging into a single system which can be located in the operating room (OR) and provides faster feedback to determine if a tumor has been fully resected and if there are adequate surgical margins. While final confirmation is obtained from the pathology lab, such a device can reduce the total time necessary for the procedure and the number of iterations required to achieve satisfactory resection of a tumor with good margins.

Falen, Steven W. (Carmichael, CA); Hoefer, Richard A. (Newport News, VA); Majewski, Stanislaw (Yorktown, VA); McKisson, John (Hampton, VA); Kross, Brian (Yorktown, VA); Proffitt, James (Newport News, VA); Stolin, Alexander (Newport News, VA); Weisenberger, Andrew G. (Yorktown, VA)

2012-05-22T23:59:59.000Z

436

Optical coherence tomography guided dental drill  

DOE Patents [OSTI]

A dental drill that has one or multiple single mode fibers that can be used to image in the vicinity of the drill tip. It is valuable to image below the surface being drilled to minimize damage to vital or normal tissue. Identifying the boundary between decayed and normal enamel (or dentine) would reduce the removal of viable tissue, and identifying the nerve before getting too close with the drill could prevent nerve damage. By surrounding a drill with several optical fibers that can be used by an optical coherence domain reflectometry (OCDR) to image several millimeters ahead of the ablation surface will lead to a new and improved dental treatment device.

DaSilva, Luiz B. (Danville, CA); Colston, Jr., Bill W. (Livermore, CA); James, Dale L. (Tracy, CA)

2002-01-01T23:59:59.000Z

437

-CT CT)Computed Tomography(. ,. , -100 ,  

E-Print Network [OSTI]

· . · , , , , . · , " , , . · , . , . : · . ·2-4 . ·2-3 -. ·) D,DMAIC, SPC, FMEA, Control Plan, Lean) 8(-. · -. ·. ·. NPI ·. · , , .' , ·" . " * . : ·) B.A ,(-. ·4-6. ·) QFD, CtQ breakdown, DfSS, SPC, AQP, FMEA, Control Plan.( ·Six Sigma GB

Pinsky, Ross

438

Quantum process tomography with coherent states  

E-Print Network [OSTI]

We develop an enhanced technique for characterizing quantum optical processes based on probing unknown quantum processes only with coherent states. Our method substantially improves the original proposal [M. Lobino et al., Science 322, 563 (2008)], which uses a filtered Glauber-Sudarshan decomposition to determine the effect of the process on an arbitrary state. We introduce a new relation between the action of a general quantum process on coherent state inputs and its action on an arbitrary quantum state. This relation eliminates the need to invoke the Glauber-Sudarshan representation for states; hence it dramatically simplifies the task of process identification and removes a potential source of error. The new relation also enables straightforward extensions of the method to multi-mode and non-trace-preserving processes. We illustrate our formalism with several examples, in which we derive analytic representations of several fundamental quantum optical processes in the Fock basis. In particular, we introduce photon-number cutoff as a reasonable physical resource limitation and address resource vs accuracy trade-off in practical applications. We show that the accuracy of process estimation scales inversely with the square root of photon-number cutoff.

Saleh Rahimi-Keshari; Artur Scherer; Ady Mann; Ali T. Rezakhani; A. I. Lvovsky; Barry C. Sanders

2010-09-17T23:59:59.000Z

439

The MICE Muon Beam Line  

SciTech Connect (OSTI)

In the Muon Ionization Cooling Experiment (MICE) at RAL, muons are produced and transported in a dedicated beam line connecting the production point (target) to the cooling channel. We discuss the main features of the beamline, meant to provide muons with momenta between 140 MeV/c and 240 MeV/c and emittances up to 10 mm rad, which is accomplished by means of a diffuser. Matching procedures to the MICE cooling channel are also described. In summer 2010 we performed an intense data taking campaign to finalize the calibration of the MICE Particle Identification (PID) detectors and the understanding of the beam line, which completes the STEPI phase of MICE. We highlight the main results from these data.

Apollonio, Marco [High Energy Physics Group, Department of Physics, Imperial College London SW7 2AZ (United Kingdom)

2011-10-06T23:59:59.000Z

440

Muon Capture on the Proton  

E-Print Network [OSTI]

The MuCap experiment measures the singlet rate Lambda_S of muon capture on the proton. A negative muon beam is stopped in a time projection chamber filled with ultra-pure hydrogen gas at 10 bar and room temperature. In combination with the surrounding decay electron detectors, the lifetime of muons in hydrogen can be measured to determine LS to a final precision of 1%. The capture rate is then used to derive the nucleon's pseudoscalar form factor gP. Our first-stage result, gP= 7.3\\pm1., will soon be updated with the final analysis of the full statistics reducing the error by a factor of ~2.

P. Winter

2011-10-23T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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441

Muon collider interaction region design  

SciTech Connect (OSTI)

Design of a muon collider interaction region (IR) presents a number of challenges arising from low {beta}* < 1 cm, correspondingly large beta-function values and beam sizes at IR magnets, as well as the necessity to protect superconducting magnets and collider detectors from muon decay products. As a consequence, the designs of the IR optics, magnets and machine-detector interface are strongly interlaced and iterative. A consistent solution for the 1.5 TeV c.o.m. muon collider IR is presented. It can provide an average luminosity of 10{sup 34} cm{sup -2}s{sup -1} with an adequate protection of magnet and detector components.

Alexahin, Y.I.; Gianfelice-Wendt, E.; Kashikhin, V.V.; Mokhov, N.V.; Zlobin, A.V.; /Fermilab; Alexakhin, V.Y.; /Dubna, JINR

2010-05-01T23:59:59.000Z

442

Introduction to Mini Muon Tracker  

SciTech Connect (OSTI)

Using a mini muon tracker developed at the Los Alamos National Laboratory we performed experiments of simple landscapes of various materials, including TNT, 9501, lead, tungsten, aluminium, and water. Most common scenes are four two inches thick step wedges of different dimensions: 12-inch x 12-inch, 12-inch x 9-inch, 12-inch x 6-inch, and 12-inch x 3-inch; and a one three inches thick hemisphere of lead with spherical hollow, and a similar full lead sphere.

Borozdin, Konstantin N. [Los Alamos National Laboratory

2012-08-13T23:59:59.000Z

443

Precision Muon Reconstruction in Double Chooz  

E-Print Network [OSTI]

We describe a muon track reconstruction algorithm for the reactor anti-neutrino experiment Double Chooz. The Double Chooz detector consists of two optically isolated volumes of liquid scintillator viewed by PMTs, and an Outer Veto above these made of crossed scintillator strips. Muons are reconstructed by their Outer Veto hit positions along with timing information from the other two detector volumes. All muons are fit under the hypothesis that they are through-going and ultrarelativistic. If the energy depositions suggest that the muon may have stopped, the reconstruction fits also for this hypothesis and chooses between the two via the relative goodness-of-fit. In the ideal case of a through-going muon intersecting the center of the detector, the resolution is ~40 mm in each transverse dimension. High quality muon reconstruction is an important tool for reducing the impact of the cosmogenic isotope background in Double Chooz.

Double Chooz collaboration; Y. Abe; J. C. dos Anjos; J. C. Barriere; E. Baussan; I. Bekman; M. Bergevin; T. J. C. Bezerra; L. Bezrukov; E. Blucher; C. Buck; J. Busenitz; A. Cabrera; E. Caden; L. Camilleri; R. Carr; M. Cerrada; P. -J. Chang; E. Chauveau; P. Chimenti; A. P. Collin; E. Conover; J. M. Conrad; J. I. Crespo-Anadón; K. Crum; A. Cucoanes; E. Damon; J. V. Dawson; D. Dietrich; Z. Djurcic; M. Dracos; M. Elnimr; A. Etenko; M. Fallot; F. von Feilitzsch; J. Felde; S. M. Fernandes; V. Fischer; D. Franco; M. Franke; H. Furuta; I. Gil-Botella; L. Giot; M. Göger-Neff; L. F. G. Gonzalez; L. Goodenough; M. C. Goodman; C. Grant; N. Haag; T. Hara; J. Haser; M. Hofmann; G. A. Horton-Smith; A. Hourlier; M. Ishitsuka; J. Jochum; C. Jollet; F. Kaether; L. N. Kalousis; Y. Kamyshkov; D. M. Kaplan; T. Kawasaki; E. Kemp; H. de Kerret; D. Kryn; M. Kuze; T. Lachenmaier; C. E. Lane; T. Lasserre; A. Letourneau; D. Lhuillier; H. P. Lima Jr; M. Lindner; J. M. López-Casta no; J. M. LoSecco; B. Lubsandorzhiev; S. Lucht; J. Maeda; C. Mariani; J. Maricic; J. Martino; T. Matsubara; G. Mention; A. Meregaglia; T. Miletic; R. Milincic; A. Minotti; Y. Nagasaka; Y. Nikitenko; P. Novella; M. Obolensky; L. Oberauer; A. Onillon; A. Osborn; C. Palomares; I. M. Pepe; S. Perasso; P. Pfahler; A. Porta; G. Pronost; J. Reichenbacher; B. Reinhold; M. Röhling; R. Roncin; S. Roth; B. Rybolt; Y. Sakamoto; R. Santorelli; A. C. Schilithz; S. Schönert; S. Schoppmann; M. H. Shaevitz; R. Sharankova; S. Shimojima; V. Sibille; V. Sinev; M. Skorokhvatov; E. Smith; J. Spitz; A. Stahl; I. Stancu; L. F. F. Stokes; M. Strait; A. Stüken; F. Suekane; S. Sukhotin; T. Sumiyoshi; Y. Sun; R. Svoboda; K. Terao; A. Tonazzo; H. H. Trinh Thi; G. Valdiviesso; N. Vassilopoulos; C. Veyssiere; M. Vivier; S. Wagner; H. Watanabe; C. Wiebusch; L. Winslow; M. Wurm; G. Yang; F. Yermia; V. Zimmer

2014-08-15T23:59:59.000Z

444

Magnets for Muon 6D Cooling Channels  

SciTech Connect (OSTI)

The Helical Cooling Channel (HCC), an innovative technique for six-dimensional (6D) cooling of muon beams using a continuous absorber inside superconducting magnets, has shown considerable promise based on analytic and simulation studies. The implementation of this revolutionary method of muon cooling requires high field superconducting magnets that provide superimposed solenoid, helical dipole, and helical quadrupole fields. Novel magnet design concepts are required to provide HCC magnet systems with the desired fields for 6D muon beam cooling. New designs feature simple coil configurations that produce these complex fields with the required characteristics, where new high field conductor materials are particularly advantageous. The object of the program was to develop designs and construction methods for HCC magnets and design a magnet system for a 6D muon beam cooling channel. If successful the program would develop the magnet technologies needed to create bright muon beams for many applications ranging from scientific accelerators and storage rings to beams to study material properties and new sources of energy. Examples of these applications include energy frontier muon colliders, Higgs and neutrino factories, stopping muon beams for studies of rare fundamental interactions and muon catalyzed fusion, and muon sources for cargo screening for homeland security.

Johnson, Rolland [Muons, Inc.; Flanagan, Gene [Muons, Inc.

2014-09-10T23:59:59.000Z

445

The Program in Muon and Neutrino Physics Super Beams, Cold Muon Beams, Neutrino Factory and the Muon Collider  

E-Print Network [OSTI]

We outline in detail a staging scenario for realizing the Neutrino Factory and the Muon Collider. As a first stage we envisage building an intense proton source that can be used to perform high intensity conventional neutrino beam experiments ("Superbeams"). While this is in progress, we perform R&D in collecting, cooling and accelerating muons which leads to the next two stages of "Cold Muon Beams" and the Neutrino Factory. Further progress in Muon Cooling especially in the area of emittance exchange will lead us to the Muon Collider. A staged scenario such as this opens up new physics avenues at each step and will provide a long range base program for particle physics.

Raja, R; Gallardo, J; Geer, S; Kaplan, D; McDonald, K F; Palmer, R; Sessler, Andrew M; Skrinsky, A N; Summers, D; Tigner, Maury; Tollestrup, Alvin V; Wurtele, J S; Zisman, M S; Raja, Rajendran

2001-01-01T23:59:59.000Z

446

Regularized Equally Sloped Tomography Algorithm for Low Dose X-Ray Computed Tomography  

E-Print Network [OSTI]

without the conjugate gradient method used to calculateimplemented through a conjugate gradient method and can beimplemented through a conjugate gradient method and can be

Zhao, Yunzhe

2012-01-01T23:59:59.000Z

447

Regularized Equally Sloped Tomography Algorithm for Low Dose X-Ray Computed Tomography  

E-Print Network [OSTI]

of the central slice of Siemens SOMATOM sensation 64 CT3.6. The three inserts from Siemens’ image quality phantom,3.6. The three inserts from Siemens’ image quality EMMA

Zhao, Yunzhe

2012-01-01T23:59:59.000Z